There was a time in my life when me and partner lived far away from each other. I would visit as often as I could but the trip was long and tiresome and we inadvertantly discovered we would mess with each other during the night.
Sleeping naked made things easier and either one of us would reach for the other and in our sleep/exhausted state we would get aroused enough that when things came to a head, both of us were willing and ready.
It would always end (still does; bragging moment!) in very slow and sensuous love making, just on that very narrow border between dreaming and being awake.
We’re always relaxed and very in tune with each other when that happens and it usually happens when we are more stressed and have less time to be together. Sometimes the body just takes over and searches the other.
Ever happened to you?
I’m not really sure it’s the same as “exhaustion” sex, but one thing I loved is when my partner was into the aerobic exercise with me, and we’d both be slick with sweat and panting as we came back from the run/row/bike. Being almost unable to resist as entry is made? Ecstasy. Maybe the mere panting was enough, as it brought to mind the concept of being desperate for the other, or being heated and flushed was part of it, but something with the whole experience was mind-blowing.