The word "selfie" was one of the most popular of 2013, and that's because the act of taking a selfie happens all day, every day. Fans can follow (or stan) their fave celebs, actors and pop stars on Instagram and be treated to some sexy selfies while being given private access into the A-list world.

Stars pose in bed or in various stats of undress. They pucker up and more!

We've assembled the Sexiest Selfies of 2013. No, Rihanna is not the only star out there to take super sexy, naked selfies. There are plenty of singers, reality stars and more who share sexy shots and snaps, and they are not always about showing lots of skin or cleavage or sideboob or sweaty chests.

Sexy can be skin, a state of mind, a stare, a smirk or a smile. It's as simple as a curl of the lip, or expressive eyes.

Now check the Instagram selfies below. They're bringing sexy back.

Beyonce rocking Old Hollywood glam is always gorgeous. The singer is sexy and flawless and beautiful. We love the vintage, retro shades and cherry red lips.

Kim Kardashian's post-baby body and booty... Whoa!

Officer Minaj... Dominatrix on duty.

Rihanna and bubbles... Always sexy!

Selenakini! We love Selena Gomez in a suit... A bathing suit, that is.

Selenakini... Part Two!

Fellow 'Spring Breakers' castmate Ashley Benson also looking sexy in a bikini!

Kesha's eyes have it. She is sexy without showing too much skin.

Pouty boy Biebs getting inked. Pouty lipped selfies = always sexalicious.

A Miley-in-bed selfie is always sexy. She does that a lot. Stalk follow her if you want to see more.

More Miley sexiness, as Lil Kim for Halloween, with a pasty.

We know, a whole lotta Miley, but the abs, the abs. Huzzah!

...and her bootay.

Kendall Jenner does Old Hollywood glam. Wowza.

Lea Michele, swimming and sexy.

Miss Lea Michele again, doing nerdy chic.

Shirtless, sexy and swimming -- it's Cody Simpson.

Jessie J is sexy when sipping. Pretty much any selfie involving a mouth is sexxxy.

Vanessa Hudgens shows off her vamp makeup... and a nice pout.

Jason Derulo is known for posting sexy, shirtless selfies, but this bearded shot, where he is lost in thought, is much sexier.

If that snap of JD didn't work for you, well, then try this one!

Nina Dobrev knows how to send a good message while showing lots of skin. Now that's sexy.

Rita Ora can thank god for a strategically-placed pillow.

Jordin Sparks in a Badgley Miscka LBD + Jimmy Choo heels. That's sexy. Baby got back, in a whole other way.

Even though they are cheek-to-cheek, Katy Perry is making bedroom eyes with Niall Horan. Rawr! Or "ROAR!"

Lady Gaga all snug in her bed, with a tangle of hair and a Karl Lagerfeld doll, too. That's both cute and sexy.

That's Kylie Jenner and her uh-mazing bikini body. This photo can't make her dad Bruce Jenner happy. She's his lil' girl.

Um, how great are Ciara's lips? Luscious!

That's Carrie Underwood getting all pouty behind those aviators.

Ariana Grande... Here, kitty, kitty. This was around Halloween.

Ariana's BF Nathan... HAWT! Bedroom eyes, indeed.