David Tennant stopped by The Late Show last night, and host Stephen Colbert made sure to check in on his favorite Doctor before the taping. 

"When it comes to Doctor Whos, you were my favorite," Colbert said.

"Favorite what?" Tennant asked.

"No, favorite Who," Colbert said.

"Favorite who what?" Tennant asked.

I think we know how the rest of this sketch goes. Bonus: We got a few mentions of Benedict Cumberbatch.