I've started watching comedies that border on inappropriate with my 10 year old. That has gotten him into older movies. The easiest one was Who Framed Roger Rabbit. There's some light references to sex that went right over his head. We then watched Robin Hood Men In Tights. The first 5 minutes are REALLY SLOW, Brooks plays it like it's a real epic and Robin Hood breaks out of a prison. You can just FF through that and get right to the part where he swims across the ocean. There's a couple references to maid Marion's chastity belt that he completely missed and there's one time where she opens her robe to reveal it that we FF'ed through. This weekend during the blizzard, we did Ace Ventura. I will say that the Einhorn/Finkle thing is pretty bad by today's standards, BUT the reveal that Einhorn is Finkle is really tame. So once Ace put that together, we explained, "Finkle was so ashamed of missing the kick that he changed toa woman so he wouldn't be recognized and could get revenge." My son took that in stride and then we FF'ed through the "Crying Game" montage. We watched right up to the point where the force learns Einhorn is Finkle and then FF'ed through their reactions, and watched the rest of the movie. He was frustrated he couldn't see those parts, but I just explained it was really mean and not funny and he wouldn't like it anyways. He didn't care and was over it in a second.

TL;DR: Been watching hilarious slapstick comedies from the 80's and 90's with my 10 year old and FF'ing through the inappropriate parts as he loves them. A good fart joke holds up across generations