Hi WB, glad to see you have been moving on. Why did H kiss you and muck up your head, b/c they are the WAS and that is what they do best. Honestly only he can answer that and only you can answer how much you are going to let it drag you down.
I myself would continue to GAL and act as if that didn't happen, let H bring it up if it was supposed to mean anything and if he does it again maybe say "H please don't do that you have someone else now and it I don't really feel comfortable with you kissing me" keep it light hearted and then move on to another topic as though it is nothing much.
I understand this has you running around like a dog chasing it's own tail but try real hard to not let it affect you and if H ever has a proper talk to you or gives you a real reason for thinking he has changed his mind worry about it then. For the moment I would just accept that it is another one of the weird things WAS' do.
I know none of that helps your feelings much but it is so not worth trying to read anything into it, don't waste your energy as you have been doing really well, so keep it up....KDU