The Tony Award-winning actress had auditioned for a regular spot on "Sesame Street" in 2004. When she came back to film her upcoming cameo, she also brought her boyfriend, Tony Award nominee Bobby Cannavale, to the set—should he be jealous of her chemistry with Elmo?
To see what Foster and Elmo had to say about working with each other, read the interview on EW.com by clicking here.
To watch the duet between Foster and Elmo, look below: