When I got clean I really did feel a lot of remorse and guilt about the way I had behaved and the way I had treated people who were close to me. Addiction cost me my relationship with my son’s mum and pretty much every relationship I have had has been ruined by the way I had treated my partner’s during the relationships. I’m extremely lucky to have a wonderful relationship with my son’s mum nowadays she is very supportive of me and my recovery and she didn’t have to be she could of made life really really difficult for me if she so wished but I feel blessed that we have the kind of bond that we do.
Also when I was using I started out using with friends etc but as my addiction escalated I very quickly started using on my own and I preferred it that way to be honest. Obviously I can’t speak for your partner in relation to what he’s getting upto but I would say that it’s not that far fetched for him to be using on his own. I hope this helps in some way shape or form and please feel free to ask me anything you like