Even though Richard Pryor isn't here to defend himself against allegiations that he had sex with Marlon Brando, is first stand up routine pretty much solidifies that Quincy Jones was tellling the truth. The jokes start around the 14 minute mark. During his set Pryor says:
“Never f*ck a f*ggot,” he says, “because they lie. They always say ‘I won’t tell.’ They lie. They can’t wait ’til you finish f*cking them. ‘Guess who was here, honey?’”
He also talks about performing oral sex on other dudes.