Don't ever date married people. If they cheat with you they'll cheat on you. Men rarely leave their wives and in the cases of couples that I have known that had gotten divorced and then married to the people that they were cheating with , they never seemed to be very happy.
Listen to this song from LeAnn Rimes ~ the voice of reason.
Matthew , Chapter 5 , verse 28
"You have heard that it was said, 'You shall not commit adultery.'
But I say to you, everyone who looks at a woman with lust has already committed adultery with her in his heart.