AceShowbiz -

It's December which means Katherine Heigl's wedding is just around the corner. Speaking about that matter, T. R. Knight has revealed to US Weekly he's going to be there for his close friend and serves as her bridesman.

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

In related news, Heigl has been spotted shopping for bridesmaid's outfits in preparation for her wedding, supposedly to be held on December 23 in the Park City-Deer Valley area. The "Grey's Anatomy" star was seen in LA, accompanied by her mother, selecting fabrics for dresses and picking shoes for her four bridesmaids to wear on her big day.

Heigl and her singer boyfriend Josh Kelley first met on the set of his music video for "Only You" in 2005. They then got engaged in June 2006.

Heigl and Knight are close friends. They are co-stars on ABC's top-rated drama "Grey's Anatomy."