British radio host Greg James, who accompanied the singer to the Radio 1 Teen Heroes event at the palace last month , urged Camila Cabello to grab something on her way out of Kensington Palace - and she did.
The pair chuckled about the incident on Tuesday, as Camila returned to James' morning show.
"You triple-doggy-dare me? And you can’t not do a triple-doggy-dare," Camila recalled. "If there’s anything I’ve learned in my life, it’s that. So I did it."
Cabello revealed she tossed the stolen pencil into her mum's bag as she was leaving as James pretended to alert security, but now it seems they're aware Camila is a thief.
Responding to a clip of Camila and James' exchange on Twitter, officials at Kensington Palace commented with an emoji featuring a pair of sideways-glancing eyes.