Monkey Island? More like Spunky Island.
Apologies if that appears crass, but I didn't come up with it: developers Grimmstone did, as it's the name of their pornographic tribute to Lucasart's classic adventure game series.
Sadly, it's not a game where you have to trade insults with dangerous women or use rubber chickens to cross gaping chasms (it's just a theme pack for Grimmstone's porno Tetris clone), but it does have a catchy title and pictures of what looks like Governor Elaine Marley with her pants off, so...yeah.
As for the requisite porno name changes, Guybrush Threepwood (which was good enough as it was!) becomes Shortplank Hardwood, while the evil ghost pirate LeChuck becomes the evil ghost pirate LeBonq.
The Secret of Spunky Island is far from the only "homage" present in Grimmstone's Sexy Adventures On Porn Island, as it also features potentially-copyright-infringing tributes to Star Wars, Star Trek and The Sims.