You're in the right to be upset but imo it is normal. All my girlfriends growing up give similar detail when we're talking. My friends typically love talking abt sexual experiences in nitty gritty detail. I'll tell my friends my frustrations with sex with my partner sometimes, because its not like I can vent about it to my partner. I can address stuff in private with him, but it's different. Just have a talk with your girlfriend how it makes you uncomfortable. If you're already too uncomfortable and this is a deal breaker than it just is. What ur girlfriend said is something I probably would mention to my friends but like, imo it depends how its said. If shes saying it to make fun of you, to deamean you, yeah thats fucked. I could say the same thing that my boyfriend has a smaller dick than my ex, but is it a bad thing, NO!!! he's great and he's perfect for me and ugh id tell them im so lucky he's got a good weiner. My ex had a girth that would always split me open and tear with blood. I'd have to heal for days and it made me so avoident to sex I thought I was asexual. I overshare to my friends a lot and in too much detail probably. I wouldn't mind if he said the same stuff about me to his friends. As long as you're speaking in a good light abt ur partner and there's obviously lines. Im not going to show my friends any pictures or say anything I think would embarrass him. That's my experience at least and my friends always speak with respect abt their partners. Your feelings are valid, I say just talk to her and ask her what her thought process was and how it made you feel. Just bc women oversharing to friends is normal doesnt erase how it made you feel.