Watch The Sisterhood of the Traveling Pants for Free: How to Stream the Movie Online at 123Movies. . Four best friends (Tibby, Lena, Carmen & Bridget) who buy a mysterious pair of pants that fits each of them, despite their differing sizes, and makes whoever wears them feel fabulous. When faced with the prospect of spending their first summer apart, the pals decide they'll swap the pants so that each girl in turn can enjoy the magic.