Stepsister from Planet Weird (2000)

In 'Stepsister from Planet Weird,' a teenager named Adam's life takes a turn when his mother marries a man from an alien planet. As Adam tries to adjust to his new stepfamily, strange behaviors and odd occurrences become a regular part of his life. Along with dealing with the challenges of being a teenager, Adam also has to navigate the complexities of his stepbrother-stepsister relationship and the secrets of his stepfather's home planet. With windsurfing, UFOs, and a wedding in the mix, Adam's life becomes anything but ordinary.