This is shaping up to be one seriously fun episode of Castle.

With White Collar star Hilarie Burton already on board "An Embarrassment of Bitches," we can now confirm that former Smallville star Justin Hartley will also play a role on the ABC hit's 13th installment of the season. He'll portray the boyfriend of Burton's Kim Kardashian-type reality star.

Hartley is best known for playing Oliver throughout Smallville's long run on The CW. He most recently guest-starred on Chuck.

Castle, meanwhile, takes this Monday off and comes back with a new episode on December 5.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.