A euphemism for taking a shit.
Hold on man I got do a bad thing.
1. Sodomise me
2. a really crap rock band from the early '00s
line from a really distasteful RRP porn:
"mama, help me, nasty men do me bad things"
As quoted by Austin Powers in his movies, to have sexual intercourse.
"Come on baby, Yeah! Let's hop on the good foot, and do the bad thing."