A little Stones bootleg history...
In 1970, the Stones were moving from Decca records to their own label "Rolling Stones Records". But they were contractually obligated to give one final single to Decca.
So the Stones wrote "Cocksucker Blues (aka Schoolboy Blues) as that final single. They lyrics are as raunchy as the title suggests. They of course did this just to fulfill their contract and piss off the executives at Decca, who obviously could not release the song. But copies of it did make it to bootlegs.