Season 6 Episode 10
Kenneth tries to do well at his new job at running TGS, but Liz yells at him. Kenneth goes to the bathroom to cry. Liz, not wanting to use the lady's bathroom, uses the stall next to Kenneth. She hears him crying and asks what's wrong in a manly voice, and tries to cheer him up. When asked her name Liz responds with "Kenneth Toilethole."
Jack is dealing with the teenage girl.