This is just a shot in the dark, but maybe since you go to bed earlier now, and his normal routine was to stay up til midnight, possibly he dozes off on the couch because no one is there talking to him (that's how my husband is) and ends up sleeping there? I'm not really sure, I would ask....with my personality, I would've asked after the 2nd or 3rd time. LOL
Congrats on your success with quitting smoking and drinking!!!