Prince William had a group of students in fits of giggles after cracking jokes with them during a surprise video call.
The sixth formers had been on their lunch break when they received the shock call from the future King.
It came after William had been visiting medical and ambulance workers in Ipswich - and one of the group's mum, who works at an ambulance station - called her son alongside the prince.
Hannah Wickison, 18, was sitting with the unnamed boy and other pals in school when William called and began rolling out the jokes.
He asked if they were doing any work before seeing he was being fed cake - and calling the lad's mum's baking "not very good".
Hannah said he also compared one of their friends - who has red hair - to Ed Sheeran.
She said: "A friend's mum called him whilst he was visiting her at work and he was on the other end of the line.
"We were all just so shocked and didn't expect it, completely speechless.
"We were just laughing at everything he was saying as we didn't know what to say.
"He asked us if we were friends with Ed Sheeran as one of our friends has red hair.
"Then he said he'd tried her cake and told her she wouldn't win Bake Off.
"It was just really unexpected, the things he was saying - you just don't really think they'll have a joke with you I guess."
The sixth formers soon spread the word about their royal call.
But Hannah, from Colchester, Essex, said some of their friends didn't believe it was real - despite the video evidence.
She said: "We ended the call and had some lunch left and we all just sat there in silence, completely speechless, processing everything.
"Some people didn't think it was real and they thought it was a filter of him! Yeah, I won't forget that for a long time."
Hannah - who works as a lifeguard in her spare time - posted the clip on TikTok where it's hit over 600,000 views in just three days.
William's trip to the hospital and ambulance station was confirmed by East Suffolk and North Essex NHS Foundation Trust.
It tweeted last week: "It’s not every day the future king drops in!
Thanks to Prince William for visiting NHS staff at Ipswich Hospital today. The prince thanked staff and found out more about our local NHS."
Meanwhile, the East of England Ambulance Service NHS Trust also tweeted: "It was an honour to host Prince William today at our Ipswich station! More photos to come next week..."
