The very first licks or fingernail strokes on the scrotum feel very ticklish to me. Can make me let out a ticklish verbal reaction and absolutely squirm. If there is verbal tickle tease* as it happens, I will feel 'tickled' by it a little longer until the nerves get used to it and it's only erotic. For my partner, if I stroke the front of the clit over panties when she isn't expecting it, she will flinch and giggle or say it tickles.
If you're seeing "tickle torture"esque reactions for more than a few seconds in videos, it's pretty fake. In art, it's just fantasy.
That said, the male response to post orgasm torture is almost exactly the same as the reaction to being intensely tickled. If you had 10 audio clips and 5 were of a guy being badly tickled and 5 were a guy being post orgasm tortured, it would be improbable that anyone would guess which was which 100%. Since both are forms of nerve overload moreso than pure pain, the reactions are identical.
You can find online how guys describe what POT feels like. Some say it can feel painful while lots will mention "unbearable tickling" for the sensation.
Internet has produced search results of some women disliking cunnilingus because it really tickles too much (and not being ticklehphiles, it is not enjoyable and ruins intimacy for them). I believe that definitely would be true for some people as everyone can be hypersensitive on a given spot.
*I'd say context is a big mental factor. If tickle fetish verbal tease is heavy and forefront (perhaps lots of threatening teasing build up), and the ler is touching in a way intended to tickle, then a ticklee likely can/would feel ticklish sensations from the stimulation. Thrashing, cackling, begging style reaction like gargalesis on the ribs? No. But more like the feeling of a fingernail erotic stroke up the back of the neck or up the bare arms, causes some trembling, whimpering style minor giggling or hips squirming a bit.
