Just always remember, never let children be the reason you stay, because it will end in more regret...also...you have to be a romodel for those to beauties. What ever they see you endure, they will most likely grow up accepting a man like this.
So much more i would love to say, but it has all pretty much been summed up before me. No matter how much you love him, no matter how much you think..well...i don't want to be alone..or even if it is negative attention, at least i am getting attention...anything like this, you will be way better off with out him as will your children. Hang in there and if you ever need anything, we are all here.