Sure, Taylor Swift has had some famous guests join her on stage during the 1989 World Tour. But nothing — AND I MEAN NOTHING — will top Lisa Kudrow making an appearance, and singing a "Smelly Cat" duet with Taylor.

That's right ~the~ "Smelly Cat" song. The iconic musical number from Friends has been immortalized forever in Taylor Swift-ness.
Like, FOR REAL. THIS HAPPENED.
Yessss! @taylorswift13 is singing #SmellyCat with Phoebe (aka Lisa Kudrow) #Friends
JUST WHEN YOU THOUGHT THERE COULD BE NOTHING ELSE, THERE WAS ELSE.
#smellycat by @LisaKudrow. Best surprise guest EVER. #1989tourLA @taylorswift13
And it came in the form of two guitars, T. Swift and Lisa Kudrow.
@taylorswift13 & @LisaKudrow WHAT? SMELLY CAT #1989TourLA
This is literally what our children's children will read about in history books.
Here's even more video of it happening because WHAT? But also, YES.
Another clip of Taylor and Lisa singing Smelly Cat! #1989TourLA 📹 : @TSwiftOnTour
And if you're wondering what Lisa Kudrow aka Phoebe Buffay thought of the whole thing, here's your answer.
So @taylorswift13 is THE best person I've ever met. That was fun. Thanks Taylor.