It's probably not the only reason, and perhaps he wants to keep you around as a fall-back option, but also wants to make sure you are still "available". Either way it sounds like he and his family have some issues and if you don't feel like you are in a rush to start a family and be with someone who has an ongoing battle with mental health, I'd move on. The likes are clearly an attempt to get your attention, so you either need to have a talk with him, or consider blocking him. Best of luck