Rob Pattinson Swims in Underwear With Bikini-Clad Kristen Stewart

Credit: SDFL/Splash News Online

Wet and wild!

Looks like Robert Pattinson and Kristen Stewart made the most of shooting Breaking Dawn in Rio de Janeiro by the beach earlier last month.

In newly released pics from Nov. 12, the Twilight duo and real-life couple took a break -- and a dip! -- while shooting honeymoon scenes in the fourth installment of their vampire epic. See more pics from the Breaking Dawn set.

A beaming Pattinson, 24, stripped down to his black boxer briefs and jumped into the surf. Still clad in her skimpy white bikini from the flick, Stewart, 20, got soaked in the ocean alongside her man.

The once-clandestine couple have become "much more open" about their offscreen romance, sources recently told Us Weekly. "You can't not love them," one pal says. "They are the cutest."

What's their dynamic like? "She's the tough one, he's the sensitive one," the friend explains. "When Kristen's around, everything shuts down. He's completely smitten."