I'm doing the legacy challenge. And I've struggled a little with relationships in Sims 4 (it took me a little over a sim week to get mine and hubby's simselves together and married and pregnant - and ...
If he's a townie, I think you can find him in the manage households option and move him into a house. I think. But I'm not positive. I may just be blowing smoke, but I'm not at home to check my information right now. :)