Staying away from him, blocking every his contact or you can tell to his wife about all of this. Don't play with your feeling and his feeling. If you let him keep doing that eventually you will risk to fall into him. There no future in relationship with married man because he want play with you and if you are with him, there is a big chance that he will cheat you like he cheat his wife. Remember don't be stupid, there still many man in this world who is better than this f***ing cheater
novoice
