It wasn't how, when they slept spoon fashion, his arms around Ambrose, that one arm would tend to fall asleep. He dealt with the tingling pain because he didn't want to wake Ambrose by moving.
It wasn't how sometimes Ambrose would whimper and moan in his sleep, flinging his arm across Cain's body and pressing himself so close that Cain was quite stuck that way for the rest of the night.
It wasn't that Ambrose, being the slighter of the two, would get cold and eventually steel all the covers. He could deal with that too.
What bothered Cain, actually terrified him, was that sometimes he would wake to find Ambrose lying so quiet and still, that he would have to reach over, place his hand on the other man's chest, just to feel the steady rise and fall, and assure himself that Ambrose was still breathing. Then Ambrose would wake, startled, look at him, and smile.
"Good morning, Sweetheart"
Yes, he could deal with these sleeping arrangements.