Open Relationships

What's everyone's opinion of open relationships? Not that I'd ever be with anyone else. But my Partner is a SAHD and he's so lonely and battling depression which I don't know how to help him with. My heart breaks for him and I just wonder if that'd give him the company I can't since I'm at work. I don't think it'd be forever. Just until we're both in a better place. But I think I'm just being naive.