X-rated, but genuine questions

I have not had rotator cuff surgery, but I'm with someone who did. I'm trying to figure out what I need to do to reduce the risk to his healing while we're together.

The first time, about 2 months post-op, we tried having my leg up (missionary position) so he could lean on my calf. That worked fine until I got a cramp in my hamstring. Then we knew he shouldn't do a plank or lean on his elbow, but he must have because his shoulder hurt later.

Now yesterday he was very much in the mood, but had a bit of ED trouble, which he said was because of pain in his shoulder. I wanted to be on top, to avoid plank position for him, but he couldn't do that. In the end, he said he was in very much pain.

I apologize if these questions embarrass anyone. Mods, if there is a way to flag this post to let people know the title is for real, please do.

I'm looking for ideas to keep him safe, because apparently in the heat of the moment, he is not likely to take care of himself. I don't want to set him back. Abstinence does not seem to be the answer.