I agree, that line is so fine and completely gray. I think you did well, based on her reaction. I think you need to keep doing thing like that until she has another "stop that" reaction. Keep it light, with no pressure because yes, you are in an extra tight spot that if you pull too far away you look like the guy you used to be in the marriage. Maybe re-read the chapter in DR about changing the medium. Maybe next time write her a quick note to let her know you are thinking about her, or a quick text, whatever. Something she doesn't have to have a response to in front of you. That's much less pressure and I think if done just enough to let her know you're there ready if she needs you you'll be in great shape.
