Straight guy friend is pressuring me for a 3some

So I told my straight guy friend that I'm lesbian ,because he seemed to be getting a crush and I just wanted him to know that he has no chance with me .
Recently he met one of my female friends who I have a crush on , he thought we were a couple . I told him we weren't and we're just friends . He also gave her his number so they can meet in person because he also likes her too , but I got jealous because I like her too and I'm hoping she doesn't get feelings for him . I don't know her sexual orientation . He told me he thinks she's bisexual and that we should have a 3some .
I don't want to have a 3some with him and her . I prefer if I was to sleep with her that it's just me and her I don't want him in the picture . But it seems like he's trying too hard to get a 3way out of both of us .
I don't know what to do and how to get him off my back .
I even told him I have no attraction to the opposite sex and he said how does that work .
He thinks women are just either straight or bi and cannot be gay and only men can .
I have no idea what to do about this and I feel so disgusted by the way he's acting it's like he thinks he owns my sexuality . :help:

 

She doesn't know I have feelings for her .

 

I'm thinking that maybe we can't be friends if he keeps this up , I actually liked him as a person before he started acting like this .

 

I think I will , it's getting on my nerves so much, with this whole 3some mess I wouldn't even feel safe bring a girlfriend around him because he might try to come on to her .