Tina Fey and Jimmy Fallon take the best friends challenge (and cover Bruno Mars)

Former Saturday Night Live co-stars Tina Fey and Jimmy Fallon reunited on The Tonight Show, and the pals were so glad to see each other they decided to celebrate with a game: the best friends challenge, where the two faced off to find out how well they really know each other.

Tonight Show host Fallon broke out the Best Friends Box (which we assume is always under his desk, just waiting), to test Fey on her knowledge of his interests and alternate career options.

Turns out, the two don’t know each other that well, but it’s still pretty fun to watch.

Fey also joined Fallon’s barbershop quartet, The Ragtime Gals, to cover Bruno Mars’ “That’s What I Like”: