The facial expression during sex that coincides with the last thrust before coming.
Imagine the contorted 'fuck face' being pulled by the male as hes about to come, and compare to the wincing one would experience when sucking a lemon, or tasting vinegar. Hence, the vinegar stroke.
Ah man, I was banging this chick, and I was up to the vinegar stroke when my phone rang. Ruined the moment.
The last strokes of a Chap's portion, as his penile alignment reaches it's point of zenith, for purposes of draining one's gonad of manly brine, often upon a partner's tender copulative action. This fluidic joy is known to force a look upon one's face not dissimilar to that gained by downloading two or more shots of Strong Malt Vinegar, possibly whilst popping open an auto-brolly with thine own colon.
I was all keyed up, about to splash out on this chick's gash. Suddenly, and without prior warning, the sight a falling Nun tore me disappointly from the full realisation of my delicious Vinegar Strokes. Paying by the half hour, of course I began my quest anew; rather than take it out on the Nun.
The term being to give an old lady a good rodgering with the aid of lubricant (because she is too old to get wet)
Mr A, sleeps with ol' Mrs Z, with a crusty sensation involved for Mr A. Question is... With all that dryness, does Mrs Z find it a pleasure - Practice the "Vinegar Stroke" tonight and find out for your self!