Leave it up to a 4-year-old to drop a solid poop joke.

Last week, Seth Meyers invited his three young children — sons Ashe, 9, and Axel, 7, and daughter Adelaide, 4 — onto his show for an adorably chaotic pre-Thanksgiving interview.

Seth Meyers’ three kids — Ashe (L) Axel (C) and Adelaide (on desk) — cause a kerfuffle on “Late Night with Seth Meyers.”Seth Meyers’ three kids — Ashe (L) Axel (C) and Adelaide (on desk) — cause a kerfuffle on “Late Night with Seth Meyers.”

Screenshot “Late Night with Seth Meyers” via YouTube

A few minutes in, Meyers asked his kids how they got to the “Late Night” studio in New York City that day. Ashe and Axel said they had gotten there by car, while little Adelaide said she had taken the subway.

“Addy, did you like the subway?” Meyers asked his daughter.

And, at this, Adelaide gave a very funny, but honest, review of NYC transit.

“Yeah,” Adelaide said. “The subway smell like diarrhea!”

In response, Meyers, the Meyers kids and the studio audience all cracked up.

“That’s really good,” Meyers told his daughter with a huge smile on his face.

That was not all we learned from the Meyers children during their appearance. Both of Meyers’ sons are big Pittsburgh Steelers fans, Axel likes to spontaneously dance and Adelaide prefers one of her siblings over the other.

“Addy, which brother is sweetest to you?” Meyers asked his daughter.

In response, Adelaide immediately leaned over to Ashe and hugged him.

“And which brother is roughest to you?” Meyers asked.

In response, Adelaide leaned over to Axel and playfully hit him.

“But Addy, do you love your brothers?” Meyers asked.

“I love this one,” Adelaide said, hugging Ashe.

“But not that one,” she said, hitting Axel again.

This was soon followed by Axel randomly dancing, which made Adelaide giggle — so, don’t worry, there seems to be plenty of sibling love despite what a 4-year-old ham says.

As for the stinky subway cars, however, here’s just hoping that Mayor-elect Zohran Mamdani has one of his 17 transition advisory committees on the case after Adelaide’s review.