Threesome???

Kristina

My bf wants a threesome n he said I can pick the girl but i don’t want one because I don’t want his dick in another girls vagina n I’m a jealous type plus what if he rather have the other girl n not me ik I might sound insecure it just scares me n he knows that I don’t want to. Maybe one day in the future but at this point I’m not ready. Please give me sum advice on what I should do.