Search Results: old flame

I have been seeing my friends with benefits for quite a few years now. Its been off and on because he did move out of state for four years and didn't see him during that time frame. We spoke nearly everyday when he was away though. A year after he came back home we rekindled our old flame. Before he had left I developed strong feelings for him and told him about it. He wasn't upset. He actually wanted me to tell him everything I was feeling; though he never said whether or not he shared the same feelings as me and I never asked.
During the time that he was gone we both started seeing someone else. I had two children in the five years that I was with this man. And my old friends with benefits was always supportive and asking me how everything was going with my then boyfriend and children. He was also very respectful and never tried overstepping any boundaries. We developed a very strong friendship, despite not seeing each other, and my then boyfriend was very understanding (where he was in the same boat). The flame died in my relationship and he left me; though we take coparenting very seriously. We still get together once a week with the kids and go to all of our kids sports outings together.
I only went and saw my old friends with benefits twice after this point because when I saw him again it brought back old feelings I once had and I found myself falling for him all over again. I knew he wasn't in it for the long haul, so out of respect for his wishes I told him we should just remain friends. Recently he came to me and said that he was sorry for not being the man that I deserved and that he now realizes the errors of his ways and says that he let the best thing that ever happened to him slip through his fingers. He then told me he loved me. This is the first time he has ever voiced his feelings for me. He asked me out on a proper date as well and said he doesn't want to be alone anymore. He wants me.
How do I go about handling this situation? I believe him but I'm terrified.

he's cheated in the past, and still tries to get in contact with an old flame.(even after being taken)
He is with his wife at a function, and he sees the old flame looking nice and dressed up. How would he act?

Most interesting answer gets mh

For example, a guy/girl is engaged... but they still seem to be contacting old flames and pursuing them behind their partners back.
Will they stop once married?