<human>: Can you provide a brief overview of the text?

Basically my girlfriend (whom I've been with for about a year and a half) has this old friend from before she ever met me. Now I have no problem with her having male friends. Whatsoever. She gets texts from guy friends all the time I never feel weird or jealous or anything.

Just recently however we came to discussing this one certain friend. They're pretty flirty. I will admit that some of the flirting I'm not supposed to know about. I went through her phone a little bit... this guy clearly does not respect me or the boundaries of my relationship. Obviously I dont expect him to. It's up to my girlfriend to force him to respect our relationship if he wants to remain friends with her. This is an issue I will approach with her somehow.

My question now is that her and this friend (who she's known longer than she knows me) call each other SOULMATE. Now... I realize that osme friendships can be like that. Slightly flirty, pet names, whatever. However... I feel like once you're in a serious relationship you should respect your partner and cease that sort of stuff. I feel like if the soulmate thing was isolated I may be able to ignore it, but add in the flirting (which, like I said, I came upon through snooping which I feel quite guilty about but I feel as though ultimately it will be a good thing that I did so we can broach these issues before the situation becomes irreparable) and I'm really struggling.
<bot>: Am I being overly jealous/controlling to be completely uncomfortable with her calling a long time friend SOULMATE when they talk? It's hard to ignore given they sometimes flirt a little bit as well.