sit on (one's) arse(redirected from sit on your arse)
sit on (one's) arse
To be idle, especially when action is needed. You can't just sit on your arse all summer. Get a job, join a club—do something with your time! I was tired of sitting on my arse while so many people in the city needed help, so I decided to join a homeless shelter and try to lend a hand where I could.