I don't get why he needs "variety" to sleep with?

Not what he calls it and no not all at the same time. He infacts denies it.. I'm talking about a man I just had a miscarriage with.. who was my boyfriend.. we still act as if a couple and he knows im completely in love with him despite all that he has done. He was sleeping with all his girl-friends + going on hookup and dating sites to find friends with benefits to screw around when he pleased. Whilst all of this going on I would look at it as more than strange when we switch it up in the room often and he "gets it" Alot! He still romances me.. but when he looks for these girls he may have had with before(one just discovered) he'd act so very innocent and politely put how he wants to hookup. The latest.. He joined myspace. This man has dozens of accounts.. He only goes on to hookup and look at profiles(thats what i take) he'll lie and say he doesnt have myspace. But the girl he just contacted(yes i snooped) he had with her before and asked if she wanted to hookup again.. but i love how he puts "its arnold again" and his myspace name is Bobby. She happily says she'd love for him to "hit this" again.... he then said he doesn't hope she has a boyfriend and was hoping to hookup soon with her following another message with her new digits and saying she'll get a babysitter for her kids. YES, He does have commitment issues but i feel he just doesn't want to settle with one woman. WHat gets me is he tells me he likes how fit I am and likes alot about me but will never love a woman besides his mother...he searches for many hefty girls.. no offense but wtf? My friend thinks it's because he finds them the easiest to get to. I mean.. He's drop dead gorgeous.. He's 6'4" black silky skin and looks like a mix of denzel and usher with a fine deep voice and a player swag. We are currently having .. he doesn't know i saw this but idk.. Iv'e talked about gettting back into a relationship but then he said "I don't want a relationship with anyone. I don't want marriage, hell im fine without too" so says the man who downloads over 20 vids and clips a a day.. He's obsessed with . He claims Im the only one he's having with and he knows how my feelings are but then i tested him and asked "Im not accusing but if it came to you having sex with others could you tell me so i could stop.. if you can't love me its the best way for my feelings to fade" he then says "Im not asking for them to fade and why should i tell you when your not my girlfriend?" he then felt impowered to degrade me some etc. I talked about my health.. he has given me chlamydia before.. so i'm just keeping myself safe but it's hard when my feelings get in the way.. when he keeps hugging me and kissing me and treating me as if im his girlfriend.. i let go and have sex with him. why does he do this? why are there so many girls all for a hookup and most not caring if he's taken or not.. im sure some of you will tell me that he's free to do whatever... but it's the matter of my heart and the way he is to me.. he did say that probably a month or two from now he may have some more sexual partners but doesn't want to stop with me.. wtf is that all about? I wish i could leave and never look back but i have no support.. im not strong enough and I love him so much :( I'm 22 and he's 27..