You've got that boundary of living at separate addresses. As the others have said, enjoy him like a new boyfriend. Deep down I'm sure even you know he won't be living at his Dad's place for the next 12-24 months. He'll want back in eventually and he knows the conditions for his return. Until then, enjoy your new relationship.
Me: 31, W: 29 T: 4 M: 2 Kids: 3 (SS: 7, SD: 4, D: 3) Separated, still living together: Nov 2013 Separate bedrooms: Feb 2014 W working away; kids with me: Nov 2014