I am very sorry for what you're going through. However, why would you stay when he is sneaking around behind your back, lying to you and not showing the same level of commitment or respect towards both you AND the marriage? Why hurt yourself in this way? I know you love him, but for what? Someone who is a cheater, a liar and a snake? You deserve better than that. Cut your losses and leave. He doesn't deserve your love or commitment.