Looks like T.R. Knight is off the market.

The Emmy-nominated Grey's Anatomy star, who plays George O'Malley, stepped out with boyfriend Mark Cornelsen during the 2008 Elton John AIDS Foundation Oscar Party held at the Pacific Design Center in West Hollywood on Sunday.

The two held hands and looked very happy together. See below:

Mark Cornelsen and Grey's Anatomy star T.R. Knight.

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.