blue dress smurfs blue carpet heels Britney Spears boyfriend glasses sean preston
 Katy Perry blue dress smurfs blue carpet heels

Britney Spears and boyfriend David Lucado brought sons Sean Preston and Jayden James to the Smurfs 2 premiere Sunday, while Katy Perry walked the blue carpet with her grandmother and without boyfriend John Mayer.

Britney's on the soundtrack, with her single, "Ooh La La" and Perry voices the character Smurfette.

Brit was stunning in a Herve Leger bandage dress and Saint Laurent heels, while Katy rocked a Tadashi Shoji dress and Pedro Garcia heels. The two are, apparently, becoming BFF's, as they Tweeted at each other after the screening, "So great to see you Smurfette @katyperry! Can't wait for our Vegas date...," Britney posted, along with a picture of the two of them. Katy replied, "OMG!!!!! I CAN'T I'M CRYING."

Other celeb-kids who turned out for the premiere included Dannielynn Birkhead with dad Larry. She's looking more and more like mom Anna Nicole Smith every day! Neil Patrick harris and partner David Burtka brought their twins Harper Grace and Gideon Scott.

Smurfs 2 opens this Wednesday.