The sex had between two gay men with extreme scat fetishes.
Alice: Did you notice how bad Greg and Jamie's apartment smelled? It was like a New York City subway!
Frank: Well of course it did; before you came over they had a twinkle doo.
Refers to a dude's taking a whiz which includes sparkly particles due to his having recently received a blowjob from a chick who was wearing glitter-lipstick at da time.
Slick WIllie probably took a twinkle-tinkle more than a lot of guys, seeing as how he was able to "get some" from so many females over his lifetime.
Twinkle dust is when you shave your pubes on your hand and then blow it off onto your butt naked partner in bed, and then get dried up shit and knock it onto your partner's mouth.