<human>: My girlfriend and I have been in a long distance relationship for 2 years now(5 hours away) and haven't had any issues. Both of us trust each other and plan to live in the same city as soon as we graduate 1 1/2 years from now. 

Last night she told me that she talks about her sex fantasies with the guys she always sits to next in class ( ie she told one of them that she's jealous of him having sex in the library with someone). 
Now its not like she hasn't shared her fantasies before with me, but for some reason I just feel a bit uncomfortable about her talking about her sexual fantasies with other dudes as I could almost see it leading into flirting in the long run.

Maybe, I'm overthinking this as I never had to deal with this with my previous girlfriends before -- I should also mention that she is super outgoing and social girl.

Anyway, how would you guys/girls feel if your SO was talking to the opposite sex about their sexual experiences and fantasies.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: GF talks to her guys friend from class about her sexual experiences and fantasies and I'm not sure how to feel about it.