One of the big secrets of this season's U.S. edition of 'Big Brother' is that Frankie Grande is actually the big brother of pop superstar Ariana Grande. Frankie's fellow housemates have been in the dark about the whole thing - until last night.

Spoiler alert to those who don't want to know what takes place on the live Internet feeds.

In a surprise move, Zap2It reports that around 10PM PT Friday night, viewers tuned into the live 'Big Brother' Internet feed that Frankie revealed to the remaining houseguests who he really is, and confessed that is the "big brother" to pop superstar sister in Ariana. He also revealed that he had 1.5 million Twitter followers, and that he described himself as a "YouTube star" and "social media mogul."

The site also says that Frankie told the housemates that he was playing to win money for charity, and that he plans on building houses in Africa. The winner of 'Big Brother' will walk away with $500,000 in prize money.

A fan captured what went down on YouTube (courtesy of Just Jared). As you can see, some of the houseguests appeared shocked at Frankie's announcement.

So what do you think, 'Big Brother' fans? Was Frankie's revelation a smart move on his part? We shall find out!