Which ingredient is not found in a Sex on the Beach cocktail?

A Sex on the Beach cocktail is typically composed of vodka, peach schnapps, cranberry juice, and orange juice. The combination of these ingredients creates the drink's characteristic fruity flavor. Lime juice is not a standard element in this particular cocktail recipe, setting it apart from others that may include lime for a tartness or to enhance the drink's complexity. The absence of lime juice is what makes it the correct answer to this question, as it does not traditionally belong in the mix for Sex on the Beach.