Amy Schumer and Jennifer Lawrence danced on top of Billy Joel's piano so you don't have to

It all began with an "I'm in love with you" fan letter. Then, it escalated to a boating trip to The Hamptons and a screenplay collaboration. Yesterday, the budding friendship between Jennifer Lawrence and Amy Schumer solidified itself in "Squad Goal" history books everywhere (sorry) when the two appeared at a Billy Joel show in Chicago, unannounced, barefoot on his piano for "Uptown Girl."

The grand orchestration was well-documented by Schumer's friend and "Inside Amy Schumer" writer-comedian Kyle Dunnigan and her sister, Kim Caramele, producer of "Trainwreck."

Watch the surprise -- but not at all surprising -- appearance from the newly-minted BFFs, below. There is feet-kissing.