I saw the other post "Why women cheat?" I think us girls need to know how men cheat?

Please men only why did you cheat or did you ever consider it?

(don't get mad I copied this post, I think it's good having it for men and women)

I considered it once when I was in an involved relationship. I met a co-worker which I really got along with. She was older, wiser, stronger and down right sexy. We both had a relationship but one night her man and my girl where both away and she called me, I was extremely tempted. The reason for my desire was just the chemistry. At least with me the connection we had was very nice, and as friends we had lots of fun. I almost felt like I could have a relationship with her, and she gave me things my girl wasn't providing.

What are some signs in a relationship that a guy would start to consider cheating? Or can the relationship be totally perfect and he could cheat?