Oscar-winning actress Gwyneth Paltrow immediately decided it was time to get rid of a man she was once dating, when he started speaking to her in a baby voice and barking like a dog.
The Shakespeare In Love beauty, who is now happily married to Coldplay frontman Chris Martin, was horrified when her mystery man thought his unusual behaviour would impress her - and she ensured that it marked the end of their romance.
She says, "We call them dealbreakers, where you're dating someone and they turn on like a terrible song, or something, and you think, 'Oh right, that's over!'
"My number one dealbreaker: Once someone spoke to me in a baby voice and then barked like a dog and it was sort of very weird... I think that's unacceptable. I think baby talk is unacceptable to your own baby... I talk to (my baby) like a person.
"It was a few kinds of wrong."