The starlet, 19, looked lovely in a cobalt blue halter gown as she performed bridesmaid duties for her good pal, costume designer Shannon Larossi. The bowl-cut-sporting popster, 17, meanwhile, dressed down for the nuptials, styling saggy-bottomed camo man-capris, sneakers and a white jacket (click through the pics below to get a gander at his pants problem).

If Selena was bothered by Justin’s wardrobe choices, she didn’t let on: The petite pair of nearly a year shared a lip-lock and several hugs during the ceremony.

The day before, they were snapped puckering up in the sand, with Selena in a bikini and cutoffs, and a shirtless Justin once again showing off his undies in droopy denim Bermuda shorts.