Olivia Culpo Enjoys Girls Day at the Beach without Danny Amendola

Olivia Culpo is back in her natural habitat on Miami Beach, but this time she's hittin' the sand without her on-again-off-again beau, Danny Amendola -- which you couldn't care less about right now.

The former Miss Universe made Thursday a sun day with some gal pals -- including model Devon Windsor -- but she stole the show with her red two-piece bikini. Olivia definitely seemed aware of the cameras too, since she got in tons of different positions ... as if she were doing an impromptu photo shoot.

It's interesting that Olivia's back in Miami without Danny, with whom she's been hot and cold since this past fall. He's no longer a Dolphin -- dude got shipped out to the Detroit Lions earlier this month. Bummer for him ... that's a lot less beach time with Olivia.