Tips for my first threesome?

I was scrolling on Instagram and I came across this picture of this fine ass stripper I follow she lives near us. We started going on about how bad she was and then my boyfriend was like “you wouldn’t know what to do with all that.” And then I said something I forgot what it was and he was basically just like 👀👀👀 “what’s good then?” I have thought about having a threesome before but I’ve always brushed it off because I know that I’d be insecure afterwards. I trust my man...... but my biggest fear is that we’ll bring a girl into the bedroom who looks better or performs better than I do and that he’ll want to pursue her. How should I go about this?