Given his debauched rock star past, Steven Tyler is a man who knows his female anatomy. The Aerosmith singer put that knowledge to use on 'Jimmy Kimmel Live' Monday, and did his part to settle the debate over Jennifer Lopez's nipple that's been going on since Sunday's Academy Awards.

Kimmel wanted Tyler to judge whether his fellow 'American Idol' judge actually exposed herself as she presented during the Oscars. So he gave Tyler a blown up photo of the alleged wardrobe malfunction and asked him to render a verdict. So what did Tyler rule?

No nipple! And Tyler can't be accused of not taking his duties seriously, as he really took a good look at that photo. In fact, after watching his careful deliberations,we think Tyler should be declared celebrity arbitrator of all future nipple slips. It's a tough job, but somebody has to do it.