While interviewing Ciara and Russell Wilson on Tuesday during an episode of the at-home edition of his show, the comedian was interrupted when daughter Winnie, 6, rushed in to tell her father that she had lost a tooth.
“Daddy! I lost my tooth,” Winnie can be heard excitedly saying off-camera while Wilson was speaking.
"Wait, this is big news, guys. Just tell them what happened,” Fallon said while propping her up on his lap.
"I lost a tooth!" Winnie announced while Ciara and Wilson cheered.
Fallon, surprised to discover it had just happened, took a look inside her mouth.
“Oh, my gosh. Winnie, I’m so happy,” he said.
Ciara then asked the burning question on everyone’s mind: How did it happen?
"Mommy put a string around my tooth, then she tried to pull it out and then it worked," the little girl explained.
Fallon held up a bag containing the tooth — the sixth one Winnie has lost.
"Hopefully the tooth fairy knows that this happened and will be visiting you tonight,” he beamed while giving Winnie a kiss. “Oh my gosh, I'm so proud of you, buddy!"
Fallon’s other daughter, Franny, 5, then walked into the line of the camera.
"We don't even know who that is. It's just some kid,” he said.
The girls' surprise cameo marks the latest instance of them stopping by their father's program. Winnie and Franny have emerged as stars during the at-home edition of “The Tonight Show,” often appearing while their dad shoots.
They have done everything from serving as his band to helping him with his popular thank-you note sketch. They've also proven to be a tough crowd, judging one of his monologues by never giving any of his jokes a thumbs up.
So will the tooth fairy stop by the Fallon home? There's a very good chance, especially since, earlier this week, New Zealand Prime Minister Jacinda Ardern deemed the character an essential worker, along with the Easter Bunny.
And if the tooth fairy does make a trip there, we can only hope Fallon lands an interview that his girls will adorably crash.