I think you need to set some boundaries as far as R talk goes. When he starts and you are not prepared or in the mood say something like "H, I would like to talk about this some more too but now is not a good time" or "H I'm not prepared to talk right now, I think we should schedule a time to talk so we both have our thoughts together and this could be more productive."
It may be hard at first as he may balk but it will get easier if you keep it up and he will begin to accept your boundary.
