Just to make it clear, as far as I know, my husband has never physically cheated on me. However, I consider TRYING to cheat the same as cheating. The intention is there whether one is successful or not, and emotional infidelity is just as bad. Therefore, I consider my husband to have cheated on me TWICE that I know of.

a short note:

He implied to the girl at school that he was single. He only told her about me after she'd given him her number and he accidentally slipped up and mentioned his daughter, and she asked where the mother was. When they first met, she asked if he was in a relationship, and he said, "I've got three different kids by three different women," neglecting to mention that he was married to the third woman.
He would walk arm-in-arm with her on campus (joined-at-the-hip close), have coffee with her every morning, spend all his time at work--in the computer lab--with her, flirt with her, and make sexual innuendoes to her (I know this because I eventually talked to her, and she told me. He verified it all).
Anyway, when I confronted him about hitting on my best friend, he said he didn't cheat, but when the girl at school asked if he'd ever cheated on his wife, he said, "once, with (my best friend); we started something, but she backed out." (My best friend told me she had to tell him to leave three times before he would stop hitting on her and leave--he'd gone to her house to return money she lent him--before he left, he said, "I still consider us friends.") So, to me, he wouldn't admit it as cheating, but to a girl he's trying to sleep with, he said it WAS cheating.

The girl has since broken off contact with him, as far as I know. I don't know if he's set his sights on someone new or not.