Power over partners

I am "lucky" enough to have a partner who will pretty much do anything I say. Or at least he used to. Most of the time it's nice, like if I want to eat at a particular restaurant he will agree, but at times it gets annoying, like when he can't make any decisions at all. A few years ago he started to do something to harm himself that he did in order to relax because his job was stressing him out. And now I find out that he has been doing it again behind my back and it makes me upset. He stopped last time because I asked him to, but I doubt that will work again. Should I ignore this behavior, or keep bugging him about it, or some other option?