Threesome

My boyfriend asked me if I would ever be interested in a 3some. this is one of his dreams and something he’s always been interested in but just two weeks ago he was asking some girl if she was single? he’s so overprotective and won’t even let me have friends who are male from my childhood or who are close with family and since i have them he claims that it “wasn’t cheating” I’m scared on how to 1. find a girl i can trust he won’t fall for 2. how do i even find someone in general?

okokok this is really really bad but on the other hand, i have no more interest in this guy. i know he’s so bad for me and i know for a guaranteed fact i’d be happier without him but it’s so hard to leave. when he breaks up with me ( like at least once every week) i’ll just be like okay i guess we won’t work out AND HE KEEPS GOING. he keeps giving me another chance like i asked for one but in reality i want it to be over! when my friend came to visit from 2 hrs away he was jealous because he couldn’t come over too and he kept trying to make me tell her to go home. He literally drove to my house after i kept saying no several times just to zoom off like a child when i didn’t open the door. I’m so exhausted. how do I leave???