WOW, you've really found yourself in a pickle, haven't you? The guy obviously doesn't love you, or your daughter. And why on earth have you allowed his daughter to kick and pinch your baby? She (his daughter) would get a swift kick in the ascot if she laid a hand on MY baby, along with a hard slap on her face. I would DEMAND that she leave and not come back. :/ Sounds like this guy is whipped by his daughter and lets her run wild.
You and your kids deserve better than a guy like this. Take them and go to a women's shelter. God wants you out of this relationship because it is unhealthy for all involved. Not to mention the living together before marriage and premarital sex part of it. :/ And speaking of that, for the love of God, DON'T marry this turkey!! Get out now before it gets worse.
BLb, your actually correct this time when you say get out of the relationship...