Sophie thinks George Bush is the king of America.

The busty 'Big Brother' contestant made the gaffe while talking about the monarchy with Rodrigo, and had the camp Brazilian rolling around with laughter.

The misunderstanding started when the pair began chatting about whether Rodrigo would ever get to meet Queen Elizabeth.

Sophie told her pal she thinks he has a "95 per cent" chance of meeting the monarch, because the whole country knows he wants to and it would make her look like she was in touch with the people.

Rodrigo thoughtfully replied: "But I only want to meet her if she wants to meet me."

Sophie the said he would be even more likely to meet her because hardly anyone wants to in this country.

Rodrigo yelped: "I love her!"

Sophie then said: "I think we're the only country to have a queen."

Rodrigo giggled and admitted he thought was incorrect, prompting Sophie to wonder how many royal families there were across the globe, mistakenly believing the former US President has the same status.

She added: "George Bush? He's the king?"

Rodrigo laughed: "Of course not!"

Sophie exclaimed: "Oh, it's that Obama! I like him, he's the first black President. Got a really nice family."