I am seeing a maried man but he cheets on me by kissing other women anx coming on to then why? Is he insecure or does he have liw selfesteme?

He's a cheater. That is what a cheater does.
Why are you still with him? He cheated on his wife, did you not think he would also cheat on you?

LMAO!

Really? You're concerned that the guy you're cheating with cheats on you? That's absurd. He's a cheater. Welcome to his world.

He's not faithful to his wife, what makes you think he'll be faithful to you?