if you consider him good fun and have been able to look past the ugly mud clinging to him for so long, what are you so concerned about now? hush up and enjoy your good fun and his countless other lovers and him fathering illegitimate children all over the place and the std's that will surely come and your ailing mental health...go for it woman!
Well, if he's "good fun" and you don't mind his cheating ways; then, maybe it's "enough."
But, if you're asking "is he normal" ... the answer is: no.
I really cant believe that you think you can be happy after what you and this man have done peace said it better than i could i do not beleive in cheating after marriage
He cheated on his wife with you. What makes you think he wouldn't do it to you? 9 out of 10 times that's what happens. Women are always surprised when they find out that the guy they have been knowingly having an affair with cheats on them. The best thing you can do is leave him. He's not worth your time or energy. And I hope you learned your lesson and stop knowingly messing around with other woman's husbands.
I do believe peace said it all.
I'd be happy to give you some of the best advice you'll ever receive, and that is to leave him now while you have the chance and aren't completely blinded by all the "nice" things that he's done for you or your children. I hate to say it, but this shouldn't have been as shocking as you sound right now. This is the man that you had an affair with, and he is the man that had an affair with you while he was married as well. It isn't like it was that huge of a shock when you learned that he's had yet another woman weighing in on the wings as well, right?
Get rid of the guy and start over fresh.