On a recent episode of Bill Simmons' B.S. Report, guest Bill Hader talked at length about his hugely popular recurring SNL character Stefon — particularly how he and co-writer John Mulaney come up with all those crazy New York hot spots.

Hader revealed that, while there is a structured writing process behind each skits, some of the most memorable Stefon moments were produced on the fly.

"John Mulaney will put stuff in," Hader told Simmons. "He'll either tell me as I walk out to throw me off, you know, to make me laugh, or he'll put stuff in without telling me."

[H/T: Grantland via Brobible]