High school is coming to an end for the shy Gustav and his best friend, Buller. The two outsiders only think about sex and talk about nothing else. Gustav is hopelessly in love with popular Barbara, who is barely aware of his existence. But the boys' lives change completely when an alien in the form of a handsome guy named Allan suddenly drops from the sky. Without knowing about Allan's plan to take over the earth by procreating with as many people as possible, Gustav and Buller form a special friendship with him. Suddenly, Barbara also catches sight of the clumsy Gustav. In time, it dawns on both Gustav, Buller and Allan that sex is about more than procreation, and that truth changes their world forever.