I’ve always considered having a threesome outside of a relationship and it’s something I would really want to try.

I have been in a relationship for around 6 months and am so in love, we have had very few fights but there has always been this girl I found suspicious, as she is the only other girl in his life that isn’t me. I haven’t met her and he knows her because they used to go to school together. They no longer hang out or talk but for some reason she makes me really uneasy, although his lack of contact reassures me it’s fine. My boyfriend asked me if I’d ever consider a threesome and we spoke about it, I agreed I would be interested, as long as it wasn’t a close friend, and other criteria to make me feel more comfortable. Part of me is unsure because I feel like I’m doing this for him, but I’ve always wanted to, even before I met him. We were coming up with names of some girls we would consider (all my friends, ones I’d be comfortable with) until he said “there’s this girl that you don’t know, (his highschool friend), I don’t know if she’d be up for it, but shes pretty hot.”

I immediately felt like it was all a mistake, only because I can’t get past this girl, I feel like she’s taking over my relationship. He doesn’t know my uneasiness with her because she’s never been a real issue, but now I feel like I can’t watch him have sex with anyone, in fear of feeling how I do about this girl.
Help please,  I’m so confused 😦