Well, it sounds like he is a devoted dad and just doesn't have the time to give you two what you want as it stands now. He suggested moving in, so maybe he sees that as a way to spend more time with you. It would behoove you all to sit down and voice your concerns, wants, needs, and expectations.
I would also suggest that you not think of this relationship as a Couple Plus One. You are all three individuals. He's not an appendage meant to make the two of you happy. If you all treat each other all with equal respect and consideration, you can't go wrong.
Edit: About his daughters, spoiling them (as you see it), and not telling them about his relationship with you two.... First, how he parents his children is his business, not yours. Keep in mind, also, that he may not want to tell his daughters or ex about his relationship with you two because he fears it may impact his custody/visitation with his girls. This is a very real concern for divorced parents. If his ex, or even ex-in-laws, disapprove of his arrangement, depending on where you all live and what grounds can be used, they can file a complaint and prevent him from seeing his children. More than a few people have lost custody or visitation when it was discovered they were in a polyamorous situation. It's an unfair reality.
Last edited by nycindie; 10-18-2011 at 11:35 PM.