When I was 7, 8, or 9 (?), my mom used to give me enemas occasionally. I don't know if there was anything erotic about it or not, but then I wouldn't have known because I was so incredibly naïve about such things.
Later, after my "awakening" (see first time post somewhere on this site), I'd go snoop through my mom and dad's bedroom. This was a frequent occurrence, as I was home alone almost every weekend night. One night, I was 12 or 13, I found that my mom had gotten a vibrator. I used that thing on myself a lot over the next few years.
Dad also had a bunch of porno mags. I got to know every photo in every mag intimately, as I remember.
At one point, they also got a box full of 8mm movies. I'd set the projector up, watch the movies, and masturbate for what seemed like hours. They even had one movie simply labeled as "Dog". It was interesting, but that's a subject for a completely different forum.
My bedroom was directly above theirs and was not much sound insulation between the two. I could hear them going at it every so often. They would also talk about such things after I had gone to bed, sometimes at the table in the kitchen. I'm sure they thought I was asleep, but I wasn't and some of the conversations that I got to listen in on were pretty interesting as well.
The only full bath with a tub in the house was upstairs, across the hall from my bedroom. Mom used to come up and take long baths after I had gone to bed. I remember she had dad install a hand-held shower nozzle on the faucet. It was not a shower per-se, just a tub with the nozzle. Eventually, the hose broke and the metal casing on the hose peeled back, leaving a long, exposed black rubber hose attached to the faucet. For some reason, my mom did not have dad fix it right away, and it remained like that for some time. I sure enjoyed it, as it was great fun to play with and the hot water felt great going up my rear. I think mom and I both started taking a lot more baths.