<human>: So the other day I'm at dinner with the girlfriend.  Things are going great, as always, when this guy gets brought up in a conversation once again. I never really questioned it, but this time I was like "So... how often do you talk to this guy, anyway?"

She tells me they email back and forth roughly 3 times a week. I just went "Oh. That sucks."

Annnd que awkward feeling in my gut since.  The rest of the night was kinda lame because I was put off by the idea that she still speaks and is friendly with a dude she used to bang for 4 years.  We're 24, by the way, so this was 2 years ago she was with this guy. She immediately noticed I was upset, and started by saying "Well I'm not going to just stop talking to him, he's a really great friend of mine!" so I calmly said "Yeah, I know, I never asked you to stop talking to him. But it still sucks." Then it was "I don't like him that way, you're the one I care about, etc."

So that was last night and I've felt weird all day, plus I've been kind of ignoring her. I've been having conflicting emotions about it.  On one hand, I realize she's a pretty girl with an awesome personality. Dudes are gonna be gunning for her left and right, I need to have confidence and not let it get to me.

Then my mind goes, "Yeah that's all well and good but she's still keeping up with the dude she was with on and off for FOUR YEARS."

So what of it, Reddit? Overracting? Underreacting? Cats? What say ye?

Could you distill the essence of the text into 1-3 sentences?
<bot>: Girlfriend talks regularly with dude she dated on and off in college for four years. I'm not sure how to handle it.