Tamar Braxton Says Her Sisters Think She's 'Nuts' for Joining 'Celebrity Big Brother' (Exclusive)

Plus, why the R&B singer thinks she'll do well in the house despite never having a roommate.

Tamar Braxton is confident she'll do well on Celebrity Big Brother, but apparently her sisters can't say the same!

The Braxton Family Rules star opened up to ET ahead of the show's Jan. 21 return to CBS, where she admitted her sisters are a bit apprehensive about how she'll do on the show.

"My sisters think I'm absolutely nuts," the 41-year-old R&B singer shared. "Toni, in particular, she was like, 'You do know you have never had a roommate, and you are used to doing things your way.'"

"I'm nervous getting stuck in a house with anyone," she admitted. "I've never had a roommate before. I don't know how that is going to work out on this show."

Tamar did raise a good point for why she likes her chances in a house full of public personalities, however, being one of a famous family of sisters.

"To be stuck in a house with a bunch of celebrities, I guess I'm used to it," she said. "My sisters are pretty much celebrities, I guess so, but that doesn't really faze me at all."

Another thing going for Tamar is her competitive drive. 

"I'm hardcore competitive fan or not," she explained. "But because I'm in the Big Brother house, I'm really competitive and I'm ready to win some competitions."

Additionally, Tamar, who was unable to join the cast last season, is happy it worked out this time around.

"Well, to be honest, last year I was presented with the opportunity to come on the first season. And due to some contractual obligations that I had, I couldn't do it," she said. "I was so bummed and then this year again they asked me and I basically cleared my schedule. Seriously, I'm not missing another opportunity to be on my favorite show."

And as such a big fan of the show, Tamar is prepared to avoid some of the common pitfalls of houseguests, including the notorious showmance.

"I am not interested in having a showmance," she exclaimed. "You're not going to play me in front of the whole world, honey, no, no, no."

As for who she hopes walks through the door? Well, Tamar wouldn't mind seeing a certain pop legend.

"I would love if Mariah Carey walked in the door," she revealed, adding: "I don't know how much conversation you will get from me or competitions because I would be in awe."

Wouldn't we all!

As we gear up to head back to the house, watch the video below for more of this year's Celebrity Big Brother cast.