Although they’ve known each other for decades, Penn and Teller’s relationship has always been strictly professional. Their act involves a lopsided dynamic. Penn Jillette does almost all of the talking during their shows, whereas Teller remains largely silent. Teller (whose legal name is just Teller) does communicate with Penn, but he does so largely through facial expressions and gestures.

That onstage dynamic is a gimmick, and it’s been enormously successful for them both over the course of their careers. Although they work well together onstage, it seems that the two are not close in their real lives. 

“Teller and I never got along,” Penn said in an interview with CBS. “We never had a cuddly friendship. It was a very cold, calculated relationship where we thought we do better stuff together than we do separately. It turns out that respect lasts longer than affection.”

Source : https://www.distractify.com/p/are-penn-and-teller-in-a-relationship