A friend or close acquaintance who nurtures one's mother in the hot tub.

when you drink alcohol while sitting a hot tub; your blood pressure is low when you are sitting there, so when you get out and it picks up, the sudden rush of alcohol through your veins hits you like a train

When you sit in a hot tub with 3 other people and then each jizz and add food coloring to the water and try to guess who's is who's by slurping the specimen through a straw.

When someone was in a hot tub for so long that they feel drunk or high. Usually only lasts for a few minutes or more, and the person may feel light headed for a bit.

A game.

You need:
4 guys.
A rubber ducky.

Goal:
4 dudes sit naked in a square hot tub. They have to hit the opposing sides wall with the rubber ducky but only using air or water, no hands. The person who gets 10 in a row gets to pick who gets the rubber ducky up their ass.

A subgenre of Twitch Thot, who broadcasts her/himself in a hot tub, nearly nude in order to solicit donations from young boys or girls, because they have no other talent or anything that makes them interesting enough for people to tune into their streams. Twitch refuses to ban them for some reason, even though it clearly violates TOS, for sexual content.

When a woman invites a random group of men over for a hot tub party which turns into a hot tub smorgasbord of sexual acts such as obtaining clitoral stimulation from a hot tub jets, while pleasuring multiple men.