What a flex this is. Obviously Billie Eilish is a household name and I'm sure her super young fans loved this (and if they weren't fans they are now). But to sing her breakup song on a children's television show has got to be one of the cooler things she's done, at least in my opinion. Billie is so popular that she's being asked to make a version of the song for kids to be sung nationally. Let that sink in. As the ex, that's gotta be a slight blow. See Billie's Sesame Street version of 'Happier Than Ever' below.