The reason I asked is that I've never found any reference to it online. I was in the habit of recording the audio for SNL performances at the time (and for several years after) and even I didn't catch it at first. One day I was playing back the tape and suddenly had a "Wait...did he..?" moment. Rewound it and it was plain as day.
As a professional infant, I actually have a mental list of musical acts that managed to slip it past the censors. Aside from the Stones, there's also the Beastie Boys and R.E.M.
The B-52's slipped in a BS, though I saw that rerun several years back and was disappointed to see that NBC caught it. They garbled the audio and blurred Fred's lips.