A curious doctor, new to the neighborhood, finds himself in a compromising position with his step-sister and her engaged fiancé. The three, in the throes of a hot summer day, decide to cool off by the pool. The doctor's eyes wander, taking in the fiancé's tight, swim-trunk clad body. He can't help but fantasize about what's underneath. As the fiancé and step-sister share an intimate moment, the doctor's lust grows. He tentatively approaches, offering a game of truth or dare. The fiancé, eager to impress, dares the doctor to kiss him. The doctor, now hard and eager, complies, leading to a passionate, first-time gay threesome under the sun.