They've always been best friends Grey's Anatomy, and in the real world, so it's only fitting that bride-to-be Katherine Heigl includes T.R. Knight in her wedding.

The actor was among the small group of friends and family who helped Katie celebrate her recent 29th birthday, and now T.R. Knight has revealed in the current issue of Us Weekly that he'll be a member of his BFF's wedding party.

T.R. Knight, 34, is going to be a "bridesman" when Katherine Heigl finally ties the knot with her fiance, singer-songwriter Josh Kelley, 27, on December 23.

T.R. Knight will be there when Katherine Heigl says "I do."

"I'm standing up there and all," Knight said at the L.A. benefit for the Trevor Project on December 2. "I have to go and get the tux, and I am still deciding on a gift!"

Regardless of how you feel about George and Izzie as a couple, it sure is nice that these two are so close. We're excited for Katherine Heigl's upcoming nuptials!

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