Mine was cheating before we split up, and continues to see one of those women now, off and on, I think, though he denies it. I'm sure he's had others as well in the time we've been separated, but no one steady yet.
I'm sorry, Rae... it really hurts, I know. Even when you knew it was going to happen, and even when you know in your head it's for the best... it still hurts. It just does, but it will get easier.
Hugs to you!