Originally Posted by SNeacail
So you get to do all the dirty work. He gets free babysitting, someone to wash his clothes and care for his household while he gets to go out and play. He is not treating you as his primary (he will leave if you don't accept his girlfriends), he is treating you like hired help.
Decide for yourself what will make this relationship worth staying in for you. Be clear in what you need from him. If he can't be there to give you what you need it's best that you know it sooner rather than later. Also be very clear with him about what his children need from their father. He has kids, and has done for a long time, his life can't be all about him and what he wants all the time.