After all, Elmo seems equally disinterested in both...

I have a hard time believing that Elmo was traumatized by Katy Perry's decollatage after discovering that he had already "been around the block"... Compare and contrast:

So I am left with the understanding that cleavage that sings pop songs is "bad" while equally impressive cleavage that sings Bizet is "good".

Thanks, Sesame Street!