If you are thinking of having a date with a married man, it is one of the worst ideas you can have. If that guy is having a date with you, he has already proved that he can not keep the commitment and he is not faithful. So you should search for a guy who is not married and who is more responsible. The other thing is that you are going to have a painful span of life even at the end you get that guy. The only way that you are not going to have that pain is that you are just doing it for fun and nothing else, but still there are chances that you might get involved in him, so better to avoid, and remember my this advice on dating married people.
He is married and he has already made a promise to someone to spend his life with, so you can understand that he can not be trusted. The married man who can cheat his wife can do anything and he has proved this that he can not keep the promises. He only looks for himself and not to someone else, so you are planning to get that person in your life? I think its really a bad idea.
But if you are on the same point that you just want to have some fun, just to kill some time, I will again say avoid it, or you are just at your own. I can not give any better advice on dating married people. You will feel like cheating to someone. He has cheated his wife and you are the reason for it. May be some time in your life you realize this and you feel guilty about it. There is a chance that you are paving a way for destroying someone's life. So you have to think about it. You are not affecting one person's life but a complete family will be in trouble because of this. I will again give you the same advice on dating married people that you should refrain yourself from it and better find some other fun.