3rd Rock from the Sun - Season 6 Episode 2

Tommy is still reeling from his breakup with Alissa, but Sally and Harry convince him that if he can find an excuse to go over to her house, he can persuade her to watch a movie with him. When the pair leave the house together, however, Strudwick is suspicious and confronts Dick. Mrs. Dubcek suggests that they could have eloped, so Dick and Strudwick rush off to track them down before there's a baby on the scene, managing to accidentally abandon Mary in the process. Meanwhile, Tommy has rented a scary movie to watch with Alissa, in the hope that it might bring her into his arms, but Sally and Harry decide to show up and make it more real.