why bi?

One of the things that really bothered me during our relationship was his need for porn, another was his interest in men. When we would go out and he would get drunk, he always was joking with men (sexually). I found it strange and many times I would ask him if he was gay. There was one occassion where I found out he was talking to men on line about doing them sexual favors, etc. It made me sick, but I stayed. Right before he left me in march, I saw an email that said his subscription to bisexual playground has expired. He is living with this woman right now that is his soulmate. His words...she completes him.....was he that turned off by me that he turned to men? He posts stuff on his fb about how he can't wait to get off work to go spend time with her, make love to her. Etc etc. He never had time for me. This is just not right. I know I am fat and unappealing, but to turn to men until you find the right woman. That is just wrong!!!