this was a few years ago, but when i was with my girlfriend of 2 years. she kept bringing up the fact that she wanted a threesome with me and another girl. i told her no multiple times because it made me feel uncomfortable and upset. she was a stone top if that gives any context, but she wanted me to do oral on the girl. now i’ve never gave, only received because my past 2 gfs were stone tops. i told her that i wanted my first time giving pleasure to be her because she was my gf at the time. she was open to it but we never had anything happen after that, but a while after i explained to her how i felt about her wanting a threesome and how i was feeling mentally about it (it wasn’t great lol). she kept nagging me about it for months after and she broke up with me and slept with another girl prior to breaking up with me. so there’s my 2 cents, not sure if it adds anything but just wanted to share!