Suzie:
I just had a great idea (at least in my own mind

).
Try visual aids, guys do better with spatial things than language. Ask him what his hopes and wishes for the relationship look like, then tell him yours (I bet they overlap) and draw something symbolic of this ideal. Then draw where you are, and draw a path. Ask him, how do we get there?
Then draw the word AFFAIR on the path and explain that you still need his help moving the affair of of the path so you can both get to your desired destination. Just nudge it enough so there is a way "through" and remind him that this is all you are asking. And, show him again that you are both trying to get to the same place, that you are not trying to find a way to leave him.
Couldn't hurt could it?
DT