T.R. and Mark spread their wings at the Butterfly Ball

T.R. Knight and his boyfriend Mark Cornelsen, who have been snapped here and there are various events and while mulling about Los Angeles, walked the red carpet the other night at the 7th Annual Chrysalis Butterfly Ball with an assortment of other celebs. (The organization helps homeless and disadvantaged individuals become self-sufficient through employment opportunities.) It's great to see the gay fellas doing photo op duty just like any other Hollywood couple ... remember when gay celebs generally opted to keep their significant others off the press line? Yeah, like ... up until about last year.

A few more pics of Knight and Cornelsen and some of their pals (like Grey's co-stars Eric Dane and Katherine Heigl and Brothers & Sisters' Balthazar Getty) after the jump!

T.R., co-star Eric Dane and wife Rebecca Gayheart, and Mark

Balthazar Getty

Ashton and Demi

Katie Heigl, looking old-Hollywood gorgeous