weve dated 2yrs and he wont be intimate with me and he cheated in beginning but...

[Me]

...says it was a mistake, why? this man is 40 yrs old and hes into fetish sex, however we have talked about it many times and he said he cares and loves me but i just found out the girl he cheated with is an ex of 5 yrs whom he convinced her to move away and they're still talking, once he told me she had better body but loves mine - i told her via myspace when i found out and told her in letter that i was offended he downloaded her porno pics and they need to stop - she apprently isnt a woman of respect and continued to txt him so i ended up breaking up with him and told him either its her or me . two months later he said it was me and wrote her a letter saying he couldnt be the man she needs for her and her son yada, yada.. its been 4 mths and i found out their back to talking on myspace when he told me he didnt have her number or anything anymore..ohh he also wants 3somes with me.. is it me? my ego is now shot,i dont feel attractive no matter what i do.. ive never had a man turn down a woman who wanted him all the time and my advances and talk about threesomes while we are having sex or me spanking another woman..does he have sex problems? or is it me? he says he dont believe in monogamy but is willing to try only for me and nothing has changed but now were fighting and never use too.. however im thinking he in love with her too? cuz hes been talking to her behind my back for 1 1/2 before i caught him last december of 09', am i wasting my time? im sick of stagnant sex and told him - 2 yrs of lack of intimacy is a bad problem and hes not trying..need advice please