Fapping ? with a partner ? I would think yes. In fact an emphatic yes. Imagine this, we were wandering through the desert for millennia (before and after opposable thumbs - trust me that is important) and we were in clumps of a few 100. We didn't find food, but we did find the right one at the right time a plenty.
Of course we also wandered alone, but for a lot less time.
Then we developed opposable thumbs.
Then we could without the "right now" one.
Your call. But partner - I'd say definitely.
Honestly here - There is a evolutionary reason erections hurt after a few days. Men had to partner up like every other animal else human race would have gone extinct.
Thanks.
Srinath.