Credit: Splash News Online

It's The End of Twilight as we know it -- but Robert Pattinson and Kristen Stewart won't be saying goodbye any time soon.

On a balmy night on a secluded St. Thomas beach April 22, Stewart, 21, and Pattinson, 24, did what comes naturally: Barely clad (she in neon-green bikini, he in a dangerously low, wet swimsuit) the on- and off-screen lovers packed on the PDA while cameras rolled. Only Us Weekly has the exclusive photos of the top-secret, super-sexy shoot.

It was an emotional night for the costars and the Twilight Saga's entire crew: After 4 years, the duo were finally filming one last honeymoon scene for Breaking Dawn, the two-part finale in Twilight's mega-franchise.

"They were kissing and pawing at each other like they couldn't resist," one onlooker says of the art-imitating-life scenes.

"She wrapped her legs around him as they kissed," another observer says.

The twosome, whose real-life romance is two-years plus and stronger than ever, celebrated the wrap with a private dinner at the Ritz-Carlton's Bleuwater eatery.

"They're madly in love!" an insider tells Us.