Thread: cheating men....

hello everyone,
i am new, this is myfirst post. here's my situation, i am not really looking for advice since i am done with this "relationship" i guess i just want opinions here.
i met a guy in march of this year. we met at a retreat. he was married and i was/still am, in a serious relationship. i had a lot going on during that time...had an ill family member at home and completely lost my sex drive. while we were on the retreat we ended up sleeping together. it felt great and i was able to regain what i had lost..my high sex drive. the retreat was a week and we had great sex ever since.
since then my sex life with my boyfriend has been wonderful and i am very greatful for that. as far as this other guy goes we have seen each other off and on since march. however because we aren't on the retreat anymore and aren't far away from where we currently live, the excitement and motivation to want to keep our "f*&k buddy " relationship isn't worth it to me.
he texts me constatnly though and still tries to get with me. i'm so sick of it.
last night i came out and asked him....why do you want to sleep with me so bad?...
his response: you are my type of girl, slim , tall and very sensual....
my response: you are married
his response: i know it cofuses me too. everything in at home is great, i don't know why i'm doing this..

i'm over him. completely, i will not be communicating with him anymore. my question is: why do men cheat then if everything at home is ok? or is there more that he isn't or doesn't want to tell me?
just curious, thanks!