Christina Aguilera and beau Matt Rutler took her son Max to karate class on Saturday, and while the pop diva wasn't all that thrilled, her little boy couldn't contain his excitement. What a cutie!

While Xtina wasn't in the best mood today, Ellen DeGeneres made her crack a smile the other day when she asked about her co-stars on The Voice ... specifically Cee Lo Green's apparent problem with flatulence. The singer, who turns 32 on December 18, told Ellen, "[I'm sitting] between Blake and Cee Lo with his gas over there ... That's why I have the fan, you know." Xtina quickly added, "I love you Cee Lo. Don't be mad. Everybody knows."

Oh, like she never toots? Come on...

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Christina Aguilera is an open book, and we love it!

While sitting down with Ellen DeGeneres, The Voice judge revealed that she LOVES to be nude. She even rocked her birthday suit on the cover of her latest album Lotus.

During the chat, XTina told Ellen:

"I like to be free. Sometimes the less clothing the better. I’m just comfortable in my skin and my body.”

You go, girl!

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We're not sure what's more over the top -- Christina Aguilera's spray tan or Nicki Minaj's hair!

We'll give Xtina a hand for lopping off the pink tips and going for a sleek bob, but how about this purple Pamela Roland dress? It doesn't really do wonders for her body, and the orange hue of her skin isn't the best match for the lavender frock. But again, bonus points for the hair...

On the other hand, Nicki killed it with her look, even if it is a bit on the neon side. Come on, would you really expect her to go for a subtle LBD? This girl is all about flashing her brights! And it must be her lucky dress, because she just won her first award of the evening, for Favorite Rap/Hip-Hop Album for Pink Friday: Roman Reloaded. Congrats!

Christina Aguilera and Cee Lo Green hit the stage during The Voice to perform "Make The World Move" ... the latest single off her new album Lotus.

Wearing a big afro and sparkly costume showing off her massive cleavage, Xtina worked her curves all over the stage. Cee Lo sported a white pajama-looking get-up for the duet. Thankfully, he kept his curves covered up.

Looks like these two powerhouses have another hit on their hands!

Red, white and booty!

The Voice mentor Christina Aguilera and beau Matthew Rutler left their favorite restaurant Osteria Mozza in great spirits.

31-year-old Xtina, sporting blonde and pink hair, even rocked skintight jeans with stars. Perfect to get in the mood for today's election.

Wonder who she's voting for? Either way, we vote that she gets her hair back to a solid color. But still love ya, girl!

But this wasn't just any performance -- the pop diva kinda seems to be making fun of her latest single!

Christina Aguilera sang along while host Jimmy Fallon punched buttons on his iPhone to re-create the song's intro, and the Roots backed Xtina by banging on coffee pots and water cooler jugs with pencils. Yeah it doesn't make any sense ... just watch the video above!

Christina Aguilera and ex-hubby Jordan Bratman were snapped leaving Max's school separately on Halloween, and even though we didn't get a peek at their son's costume, Xtina was dressed up enough for all three of them!

This has to be her fav holiday, right?

We're not exactly sure what Christina Aguilera was dressed as on Saturday night, but we're glad she's still madly in love with beau Matthew Rutler!

The pop star and her steady boyfriend were spotted on their way out the door to a Halloween bash, and the duo looked like they might have been doing a little pre-partying at her Beverly Hills mansion beforehand. Hey, as long as her son Max was with a nanny or daddy Jordan Bratman, nothing wrong with that! But hopefully she doesn't try to steal his thunder with another sexy costume when they go trick or treating on Wednesday night!