Threesome.

I would never want to have a threesome if I'm in a relationship but my boyfriend has always wanted one especially with another girl and I've told him why can't we have one with a guy and he's always like "noo I don't want another guys hands on you or another guys dick in your mouth or inside you or ANYWHERE near you" and I always tell him "that I don't want any other girl around him or on his dick or sucking his dick or giving him the pleasure IM supposed to be giving him" and he always has to be like "but babe she could give you pleasure also not just me " and I always tell him that I don't care I don't like it and we're not doing that at all! but he just never seems to understand ..😭idek what to tell him anymore. 😭😩how would you girls feel?