Prince William gave many people a surprised look when he was asked what his favorite is. He and Princess Kate recently appeared on the BBC Radio 1 show Going Home when they were asked which emoji they used the most when texting.

“Is this a clean thing or is this a family one?” William asked. “I’ve been told not to say the aubergine, so I’ve got to pick something else.”

Aubergine is the British-English word for “eggplant” which the emoji is often used to signify a penis.

“It would have been the aubergine, but I’m saying now — because I’ve got to be all grown up — it’s the one where the eyes go up and down and the mouth’s out,” William continued. “What’s that one? The slightly crazy one.”

“He said the aubergine emoji, this is brilliant!” host North said.

Host Hope added, “He knows. He’s got a dirty mind.”

Kate had more of a PG answer.

“Mine’s probably going to be the heart with then the crying emoji,” the Princess of Wales, 41, said. “The hysterical laughing when things have gone wrong.”

Prince William and Prince Kate Speak on Mental Health

In honor of Mental Health Day which was celebrated on Tuesday (Oct. 10), the royals shared they plan to be part of destigmatizing mental health.

“Today, more people feel empowered to talk about their mental health than ever before. This is a major step forward,” she said previously at a forum on the subject. “William and I continue to be inspired to see young people, like you all here today, leading this charge — being particularly brave in having some of those conversations yourselves. As a generation, you value and talk more about your mental health than any before you — something we truly admire and applaud.”

As for William, he chooses to laugh as a part of maintaining positive mental health and well-being.

“Humor for me is a big deal — I love to laugh,” the Prince of Wales told the hosts. “You’ve got to look at the lighter things in life sometimes to feel good.”

“Time with my friends, time with my family,” he added. “Things like that really matter to me.”