I always wonder how the biggest pop stars in the world like Christina Aguilera deal with not being 22 anymore. Their sex appeal is one of their biggest aspects, and while the look is there, they play it for all that it is worth.

Looks come so easy before 25, right? Not much working out is required, the skin is tight enough to bounce an anything on, life is good. Then, as our skin gets looser, our brains (hopefully) get sharper. Christina shows her depth of experience when she mentors, encourages and teaches on the Voice, so it seems she's learned a lot in her entertainment ride.

In her photo shoot in Maxim, she shows she's still sexy as an award winning pop star in a man's button down can be.

is white hot on the cover of the October issue of Maxim, wearing little more than a black bra that can barely contain her, a crisp white men's shirt and a pout.

As she returns to Season 5 of 'The Voice,' the singer showed off her toned body and a softer makeup look, ditching her trademark red lips (which are a little tired and predictable) in favor of a pale pink pout and messy white blonde hair. So sexy.

The issue drops on Sept. 17 and in the feature, Xtina talks about sexiness and singing!

She said, "I'm such a down-to-earth girl, I'm comfortable in just a jersey and boy's underwear. Trying too hard to be sexy is the worst thing you can do. Sexiness should be effortless."

Well, it looks she's mastered effortless sexiness, that's for sure.

Xtina also doesn't need her partner to sing to turn her on. In fact, it's quite the opposite. "The quickest way for me to feel weird and run for the hills is if somebody sits down and serenades me with a guitar," she said. "It's not my thing."

Xtina also dished on her former Mickey Mouse Club pals – Justin Timberlake and hunky actor Ryan Gosling. Who was cooler? She'll never tell, instead choosing to be diplomatic with her answers.

"They were both very charismatic, but I think I have to shy away from the question," the singer and coach said. "I don't want this to bite me in the butt later. They were tight, you know. They'd walk around together all the time, same as me and Britney would. Now look at us. It's funny how that played out."

Oh, and BTW, nice rack, Xtina. God, she's gorgeous.