Well, I think I'm just going to start flicking his nose whenever he does that.
And with the head on the chest. I don't stand over his head, and I usually make sure he can't hit me if he raises up. Usaully when he does this I'm standing on the side of his head and he puts the side of his head on my chest. It's really not even laying his head on me, it's more of he has little bit of cantact and gently putting it close or so it's brushing up against me, or his nose is touching. Sometimes he'll start breathing with me. It's really sweet
I don't know if he's trying to groom my back or not, and I'm not going to find out. I move away the minute he starts to reach his head over my shoulder, because it's not a gentle pull back, he almost puts the full wieght of his head and neck on me and it's heavy!