Eh... I just think, in a trusting R, the guy should just try whenever he wants to try without trying to read the situation too much. Your W can say no or give you the code word for stop.
At least, that's how I wish my H would handle me. I'm more than capable of telling him if he's all over me too much.
How are you supposed to get into a satisfying groove without acting on your natural urges when they arise?
