Fallon was asking the actress about her kids when Moses walked into the frame.
“Oh my god, look at this. Look who just popped in,” Paltrow said. “Look at how big he is.”
When Fallon asked Moses how he was doing, Moses replied, “I’m good, thank you. How are you?”
Moses later revealed that he’s now 14 years old, and Fallon looked amazed.
“I know. It goes real fast,” Moses' Oscar-winning mom quipped in response.
Moses is Paltrow’s son with her ex-husband, Coldplay frontman Chris Martin. The couple, who split in 2014 after 10 years of marriage, are also parents to daughter Apple, 16. Paltrow has since remarried TV writer Brad Falchuk, and Martin is dating actress Dakota Johnson.
While Moses may have superstar parents, he's dealing with the same struggles as other teens during the coronavirus pandemic.
“I’m doing all that I can,” he said when Fallon asked how he’s hanging in under the circumstances. “I’m trying to stay happy by just finding whatever is entertaining and doing it.”
Will Moses follow in his father's musical footsteps? Don't be surprised if he does.
“I’m really into music. I like to do it a lot,” he said, prompting Fallon to ask what instrument he’s focused on at the moment.
“Right now, I’d say I’m playing guitar the most, but it used to be piano for a while, and then I started doing guitar lessons again,” Moses said.
Fallon answered, “We’re going to have to jam out, maybe when this thing’s over."
Moses then left so his mother could finish the segment — but not before she gushed about how much her son "loves" Fallon.
“He’s your fan, both in real life and on TV, so that was very cute,” Paltrow said.