you enjoyed the attention he gave, it further developed when he actually helped with your academics.

when he moved on to xxx topic, usually the first response from girl is to get disgusted or worst block the male altogether, but you told yourself is ok with it

knowing his background, consciously you know this is a bad idea, but subconsciously you want him badly, you want the thrill he can give, the vitamin D you crave, you still entertain him and not cut him off like any sane person would do

now go, go for the love you wanted, separate him from his wife, and live a life happily ever after