My girlfriend and her coworker....

Let’s talk about this:

So, my girlfriend and I live together. I’m a pretty introverted person, while she’s very social. When she started her new job at a convenience store, there was this older male coworker who constantly teased her and joked around with her. Whenever I went to pick her up, he would always come stand close to her, and my girlfriend would play along with him. Sometimes they would even swap phones right in front of me.

One time, during her shift, I secretly went to see what was going on and saw them sitting together. When I called her, she told me she was alone. I ended up arguing with her, and then she slapped me and walked downstairs. That guy happened to be right there. It seemed like she had called him to help her go look for a new place to stay because she didn’t want to live with me after our fight.

I was really confused. In the end, that guy came up to talk things out with both of us and “mediate” what was going on, until things were resolved and we made up.

But just a few days later, he added my girlfriend on LINE and started chatting with her. Even though the content of their chats seemed like normal friendly conversation, they still went places together a lot when I wasn’t around.

So now I’m wondering:
Should I still trust my girlfriend?
After going through all this, should I still feel confident in this relationship?

Here’s how I see it:

I’m going to be direct from the very first line:

Your feelings are not “overreacting”.
And this whole thing… is way bigger than just “a coworker.”

Let me lay it out as a story first, and then break it down into clear points so you can see exactly where you’re standing, somewhere between:

“I’m just jealous because I’m introverted”

and

“She’s actually playing very close to a line that goes beyond just friends.”

And in the end, we’ll figure out
what kind of trust you can give her,
and how far that trust should realistically go.

🎬 Scene One: Introvert vs Social Butterfly – a couple of opposites

Let’s set up the picture simply:

You: Introvert

Your quiet world is your safe space.
Love = comfort, stability, trust.
You don’t need a crowd—just a girlfriend who’s on your team and on your side.

Your girlfriend: Social type

She’s talkative, playful, good at mingling.
She works at a convenience store → meets lots of people, new coworkers.
There’s this “older coworker guy” who’s smooth, chatty, likes to joke with her.

When you go to drop her off or pick her up, what you see is:

That guy always comes in close.
He teases your girlfriend.
Your girlfriend jokes and laughs with him.
Sometimes they even swap phones in front of you.

The question is:

If this happened to anyone else, would they feel weird about it?
Answer: 90% of people in relationships would feel something.

Swapping phones isn’t just “borrowing a device to make one call”.
It’s a signal of closeness + mutual trust between the two of them.

If it was a close female friend, no one would think twice.
But here it’s a male coworker, and your girlfriend is interacting with him in a way that pushes you out of your comfort zone.

This is not about you being an introvert.
This is about relationship boundaries.

🎬 Scene Two: The day you secretly went to see her – and found she wasn’t “alone”

This event is crucial because this is where trust took a hit.

You went to check on her.
You saw her sitting together with that coworker.

You called her.
She told you she was alone.

This is where it “pops” clearly.

The problem isn’t just that she was sitting with him.
The real problem is:
Why did she lie and say she was alone?

Let’s translate that into emotional language:

If she truly believed it was just “harmless friendship,”
she wouldn’t need to lie.

The lie itself means she already knew
that “if you knew she was with him, you’d be uncomfortable,”
and she chose to hide that instead of addressing your feelings.

The moment there’s secrecy, trust is shaken.
This is not “you being insecure.”
This is about honesty vs. her personal comfort.

Then you argued.
She slapped you, then went downstairs.
And it looked like she called him to help her go find a new place to stay.

After that,
he comes up to “help clear things up” between you and her.

So now you have a triangle:

You = the actual boyfriend
Her = in the middle
That coworker = the guy who appears in every tense scene

This is not a healthy setup.
It’s a three-way emotional dynamic where you become almost like an outsider in your own relationship drama.

🎬 Scene Three: After “clearing things up”… he adds her on LINE and moves closer when you’re not there

After the so-called resolution:

He adds your girlfriend on LINE.
They start chatting often.
The chat content looks “normal, just friends.”
But the pattern is: they go places together when you’re not around.

This creates a very specific feeling:

Whenever there’s a problem between you two, this guy seems to appear.
When you’re absent, he’s present.
When you’re unsure, she doesn’t tell you the full story.

This doesn’t automatically mean they’re definitely having an affair.
But what is clear is:

He has become a special person in her orbit.
She has allowed him to occupy that space.
And you’re left guessing whether it’s “just friends” or more.

In this situation…
Even if someone says, “Don’t overthink it,”
that person simply hasn’t been in your shoes.

🔎 What’s the current “status” of this relationship?

Let me break it down fairly for both sides.

On your girlfriend’s side

Things that are understandable / possible:

She’s very social → she connects with people easily.
She might genuinely see him as “just a playful coworker.”
When she’s stressed from fighting with you, he becomes someone she can “escape to” for emotional support.
She might not be very good at handling the feelings of an introverted partner, and thinks “I’m not doing anything that wrong.”

But… here are the worrying parts:

She lied about being alone when she was sitting with him.
→ That means she chose to protect her own atmosphere over your sense of safety.

She slapped you during an argument.
→ Physical violence = a major red flag.
Conflict happens in relationships, but putting hands on a partner is crossing a serious line.

She called him to help her look for a new place right after your fight.
→ That means she pulled another man into your relationship drama and used him as an emotional & practical escape route.
That lowers your position in this relationship.

After “clearing things up,” she still chose to let him stay in her life:
→ Added him on LINE, chats with him, goes places with him.

It sends a message:

“She’s willing to keep him as an important presence.”

To put it bluntly:
She is not protecting your feelings as much as a girlfriend should.

On your side

You’re not wrong for feeling insecure.
You’re not wrong for going to check on her,
because things did feel off, and then you caught her lie.

But the part you have to be careful about is:

Don’t fall into the trap of saying,
“You’re not allowed to talk to him at all,” in a controlling way.
Don’t try to control her entire social life out of fear.
Don’t use your fear to erase her right to have friends.

What you should focus on isn’t:

“You’re banned from having male friends.”

But rather:

“What are the boundaries of having male friends while you’re in a committed relationship?”

❓ The big question: “Should I trust her?”

I’m not going to give you lazy answers like
“Just trust her” or “Just break up.”
That’s too cheap for something this complex.

Let’s break it into three layers:

1) Trust Level: “Maybe she hasn’t gone as far as outright cheating yet.”

From what you’ve told me,
there’s no solid proof they’re having a full-blown affair.

But…

Their closeness is beyond your comfort zone.
It’s starting to cross the line between “friend” and “something more” when it comes to transparency.

So yes, you might still trust that she hasn’t physically cheated,
but you also have to admit:

She has opened the door to a certain kind of chemistry with him.

2) But the level of “relationship trust” between you two has clearly been shaken.

A girlfriend who:

Lies about being alone while sitting with another man
Hits you in an argument
Brings that man into your conflict
Keeps him in her life afterward as a regular presence

…is not someone who is guarding your heart very carefully.

The degree of trust that should exist in a stable relationship
is no longer full.

You’re not overthinking.
You’re simply seeing that:

“Maybe I love her more than she’s protecting my feelings.”

3) Can you still trust her? — Yes, but it has to be conditional and with clear boundaries.

“Trust” doesn’t mean:

“I’ll shut up and suffer quietly while she does whatever she wants.”

Adult trust is:

You set clear boundaries.
You watch whether she’s willing to respect them.
If she doesn’t, then you respect yourself instead.

🧭 So what should you do now? (Let me give you steps.)

🥁 Step 1: Be honest with yourself first

Ask yourself directly:

Are you honestly okay if she keeps going out with him regularly?
If three months from now, everything is exactly the same, can you handle it?
If one day you find out something did happen,
will you regret not setting boundaries earlier?

Answer without lying to yourself.
This is not about being possessive.
It’s about choosing your mental and emotional quality of life.

🎯 Step 2: Talk to her calmly but clearly (not in the heat of an argument)

No drama.
No sarcasm.
Just this kind of talk:

“I want to talk about something seriously.

About you and that coworker at the store.
I know you’re very social and you might genuinely see him as just a friend.
But for me, there are several incidents that really made me feel uncomfortable.

Like the day I called and you told me you were alone,
when you were actually sitting with him.
Or when we argued and you slapped me, then called him to help you go look for a new place.

That made me feel like,
whenever we have problems, he’s always there in the middle of it.
It made me lose confidence in our relationship.

I’m not asking you to never talk to him again.
But I need some boundaries that make me feel safe in this relationship too.

I’d like you to:
– Stop lying that you’re alone if you’re actually with him.
– Reduce going places alone with him.
– And if you do talk, let it be clearly about work or normal group stuff—not private, secretive things.

If you feel like I’m asking too much, tell me.
But if you love me the way I love you,
I want to see you choose to protect my heart more than you protect your closeness with him.”

Yes, it’s long.
But this is how you talk like an adult in a relationship.

You’re not accusing her of cheating.
You’re explaining how her actions are affecting your heart.

🧱 Step 3: Judge by her actions after this talk, not just what she says in that moment

Things to watch:

Does she admit that what she did actually hurt you?
Does she apologize for slapping you and show that it won’t happen again?
Is she willing to create distance with that coworker to make you feel secure?
Does she stop with the small lies?
When she goes places with him, is she upfront about it, or still hiding things?

If she:

Talks nicely to “end the conversation,”
but changes nothing in her behavior…

That’s a clear signal:

Your feelings are not high on her priority list.

🚨 Step 4: Ask yourself clearly—“What kind of girlfriend do I want?”

Imagine the future:

Option A: A girlfriend who still talks to male friends, which is fine—but with clear, healthy boundaries.
Option B: A girlfriend who pulls another man into your arguments every time you have a fight.
Option C: A girlfriend who cares about your feelings and is willing to “step back” from certain people to protect the relationship.
Option D: A girlfriend who always says “he’s just a friend,” but keeps some parts of their interaction hidden from you.

Which one do you want to live with?

Your answer will tell you whether you should stay,
and if you stay, under what terms.

⚖️ Straight summary, no sugar-coating:

You are not overthinking.
Some things your girlfriend has done are over the line for a committed relationship.
Having male coworkers and friends = normal.
But lying, hitting you, pulling that guy into your private fights = not normal.
You can still trust that maybe it hasn’t become full-on cheating.
But the emotional safety level in this relationship is no longer full.

“Trust” in this case should not mean:

“I swallow everything and stay no matter what.”

It should mean:

“I speak up about what hurts me,
and then watch whether she chooses me
or chooses what’s convenient for her.”

If from here on:

She chooses you
She creates distance with him
She stops doing things behind your back
She stops using violence
She keeps your relationship as something between you two, not “you two + a third guy in every important scene”

Then you have a basis to rebuild trust.

But if she chooses to protect her closeness with him
more than your peace of mind…

Then the question is no longer:

“Can I trust her?”

It becomes:

“Do I want to stay in a relationship where I feel like a backup emotionally?”

You have a choice too.
It’s not just her who gets to decide how this story ends.

💬❤️

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