Jennifer Lawrence and Amy Schumer took a break from writing their new comedy to attend last night’s Billy Joel concert at Chicago’s Wrigley Field.

Being the celebrities that they are, Billy Joel invited JLaw and Amy Schumer up on stage during his sold-out show to dance to his hit song “Uptown Girl.” The two ladies took full advantage of the situation by jumping on Billy’s piano.

This video from YouTube captures the full performance — scroll to 2:00 to see the girls come out on stage and start shaking their booties. The ladies appear to be joined by Amy’s sister, who co-wrote Trainwreck with Amy, and several of their friends:

One of Amy’s people filmed her when she and Jen jumped on the piano. She posted the following clip on Instagram:

What a night!

Earlier this week we learned that not only have Jennifer and Amy become best friends, but the two are writing a comedy together that they plan to star in. JLaw revealed in an interview on Monday that she was flying to Chicago to work on their movie about two sisters, so the concert must’ve been a well-deserved break from writing.