Antagony Aunties: Help! My Boyfriend Wants a Threesome. My Friends Are Horrified. I’m Somewhere in Between

My boyfriend and I have been together for five years. I’m 25 and he’s 27, and we actually met when I was at university. We’ve recently moved in together, and, honestly, things have always been really good between us. Our sex life has never been something I’ve felt the need to complain about. Recently, though, he’s started talking about having a threesome with another woman. The thing is, I’m actually bisexual, so it’s not the idea of being with a woman that bothers me. I’ve even mentioned to a few of my friends that I wouldn’t necessarily be completely against trying it. Their reactions were very different — they think the whole thing is disgusting, especially because he wants it to be another woman — and now I’m starting to question whether I’m even considering it because I want to, or because I’m worried about what everyone else will think. I also have no idea what the “right” way to do a threesome actually is. Is it weird to do it with someone you don’t know? Part of me thinks I’d feel much more comfortable and enjoy it more if it was someone I already knew, but then that almost seems like it could make things even more awkward afterwards. What if I see them again? What if our friendship changes? And what if I get jealous?