You weren't having a nightmare, it was a dirty dream so script by u/Hero_for_Villainess. Details in comments
script by u/Hero_for_Villainess. Summary: at the start, listener is asleep on his stomach and moaning into his pillow. Him being asleep is the reason for the tag. Speaker is in bed alongside, and wakes up.
I wake you from a 'nightmare' in the middle of the nights as I hear you begging, but maybe you are begging for something else?
Script by u/Hero_for_Villainess