Gossip Girl star Penn Badgley was sent into shock on April Fool's Day this year (10) after an elaborate prank by his girlfriend Blake Lively left him convinced rocker Steven Tyler was his biological father.
The actor is a keen singer and guitarist and has often queried where he gets his talents from, because neither his mum nor dad are good with musical instruments.
So Lively decided to play on his uncertainty and used that to her advantage to make 1 April (10) one to remember by sending Badgley an email from a woman alleging he was her lovechild with the Aerosmith frontman.
She explains, "On April Fools I thought it would a good idea... He's very musically talented and he's always wondered how he was so musically gifted without having musically gifted parents.
"So I thought who is musically talented? Who has lots of kids? Steven Tyler! So I thought, I'm gonna say that he's your (Badgley's) father. So I created a fake email address the night before April Fools, without him realising it was the night before April Fools, and sent him an email saying, 'I had a child with Steven Tyler. I live in Maryland - where he was born - I'm an English professor. I wanna reach out to you and I'd like to have a relationship with you now that you're of age.'"
Lively went to great lengths to pull off the joke, and even got Badgley's mum and publicist involved: "I had his publicist call him in the morning and say, 'Hey, listen, I got a call from one of the magazines in New York, they got a story Steven Tyler that's saying he has a child that's also in this business, that he's hoping to reach out and connect with and this was his son.' And I had them play it off like, 'This is ridiculous.' So we were laughing all day and then his mum called him later and said, 'I need to talk to you...'
"I saw his whole life flash by his eyes in all of 10 seconds. He was obviously disappointed that his parents weren't his parents and that his whole life was a lie!"