5.07 Rise Up
Derek gets annoyed with Cristina after late night talks with Meredith. He can no longer sleep. He asks Mark for a favor which is to have sex with Cristina so he can distract her. After Mark protests, Derek reminds him that he slept with his wife. Mark finally gives in agrees to try it out. Cristina laughs when she realizes that Mark has been trying to flirt with her.
