My parents had a hot tub at the house while I grew up. We were very close to a family that shared our back fence. We even made a doorway so we could come and go in each other’s yard and house. They installed a pool. It became fun for us kids to go back and forth, jumping in the pool and then into the hot tub.
Another memory of “soaking” in the hot tub was when I was swimming at the junior college. One of the things swim teams do is shave down before a big race day (like championships). We get together and have a carbed out dinner, and shave our legs so they are nice and smooth and less resistance to go through the water. Some of the guys shaved their heads. I had one of these shave down parties at my house and we crammed a lot of the girls into the tub at one point.