I'm sure it's been done before, but I always love inappropriate stuff/sexual innuendos in the least of places (especially in games). How many innuendos have you found while playing retro video games from any console? Here's some I found (or at least I think I found)

*Playing Altered Beast for the Sega Genesis with two players, you could make the Bear form characters "hump" in stage 3.

*In Dynamite Headdy,whenever you hit Trouble Bruin, it sounds like he says "Boobs". I'm pretty sure it's supposed to be "Oops" but every time I swear that's what he's really saying.

*Toad sprite flips you off (if you look really closely) in "Super Mario Brothers" for the NES/Famicom.

*The pilot episode of the NES classic "Battletoads" game features a LOT of misleading/innuendoish scenes. A few include the mountains looking like penises, one of the Toads appearing to play with his breasts whilist saying "My hands, my hands", and the Dark Queen "raping" the princess for a split second.