Lopez, also a Tony winner for Avenue Q, posted on Twitter Oct. 18, "Going to LA tomorrow to help write an episode of South Park!"
"South Park" is now now in its 15th season.
Parker and Stone authored the Tony-winning hit musical Book of Mormon with Avenue Q songwriter Lopez. The Book of Mormon earned Tony Awards for Best Book, Best Score and Best Musical. Co-directed by Parker and Casey Nicholaw, The Book of Mormon began previews Feb. 24 and opened to critical acclaim March 24.
The Book of Mormon also picked up Tony Awards for Best Direction (Parker and co-director/choreographer Nicholaw), Best Performance by a Featured Actress (Nikki M. James), Best Orchestrations (Larry Hochman and Stephen Oremus), Best Scenic Design (Scott Pask), Best Sound Design (Brian Ronan) and Best Lighting Design (Brian MacDevitt).