Julianne Hough & Nina Dobrev -- The Bikini 3-Way On the Beach

Newly single Julianne Hough and her "Vampire Diaries" star BFF Nina Dobrev like to french ... braid their hair on the beach.

In a scene straight out of a porn film -- minus all the nudity and sex -- the orange bikini babes engaged in an innocent three-way hair braiding session with a third adult female friend while bronzing their supple flesh on a public Miami beach.