Quit 'farting around' [='messing around, fooling around'] and finish your work!
a cranky old 'fart'
(..) Okay. Rule number two. You will not bother me while I'm working. Rule number three. You will not cry or whine or laugh or giggle or sneeze or burp or fart! So, no, no, no annoying sounds. All right? Does this count as annoying? Very! I will see you in six hours. (..)2010 Despicable Me