Be very careful. You ARE rushing into things, by quite a bit. The divorce hasn't even happened yet, and he hasn't been single at all. For clarity, I went through a weirdly identical situation with my now husband and now ex best friend. We rushed into things too soon and he couldn't decide. He didn't want to be married to her any more, didn't even like her but also still wanted occasional sex and comfort with her, yet was in love with me. He wasnt ready to enter right into a full committment after the scars of marriage, but i was. Situations get... complex very easily. Luckily we eventually worked it out and they not only have an effective co-parenting relationship, her and I have a respectful relationship verging on friendship. It wasn't easy.