Andy Cohen Would Bang Justin Bieber

Andy Cohen didn't hesitate when asked if he'd hook up with Justin Bieber -- it was a resounding yes -- but he's a lot less turned on by the thought of sleeping with Kim and Kanye.

Andy was on Matt Weiss and Theo Von's "Allegedly" podcast where the guys asked the "Watch What Happens Live" host a flurry of provocative questions. Andy was game ... and even brought the Biebs' penis into the convo.

The biggest surprise, though, is Andy balking at a Kimye threesome ... which he says would be a boner killer. Then he gave his F***, Marry, Kill breakdown for the 3 Kardashian sisters. Good stuff.