I note with interest that one of the most viewed British slang terms on chris' database recently is 'vinegar strokes'.
It's merely defined as masturbation, which is definitely not what it means in Northern England: here it's much more specific, although I suppose could be related.
I'll try to be as delicate as I can, but up here it specifically refers to the feeling when one is on the verge of ejaculation: the last few, umm, thrusts or whatever, as the prostate kicks in, & there's no turning back, everything goes on 'auto' as it were.
Males will understand what I mean, as the brief stinging sensation is aptly described as 'vinegar'. Females may well not understand, as I'm not one, but I dunno.
Context: "I'd just got to the vinegar strokes with her when her sodding dad knocked on the door & said " What you up to in there???".
Apologies to anyone of a delicate disposition, (like as if there are any who view this forum), but chris' definition just didn't seem correct, & I'm a linguistic slang pedant.
I may be bonkers but at least I'm British.