David Straussberg is the older brother of Mandy Straussberg. He first appeared in the episode Tornado! and reappeared infrequently over the next few seasons as Alex Jefferson's best friend. Eleven seasons after his last appearance in Slumber Party, David reappeared in Now More Than Ever, bitter, angry, and hardened to his parents' struggles in their marriage. We learn that he no longer hangs out with Alex, but rather a "different crowd", as Mandy puts it. He began to cut himself off from his family until, in Life, in the Third Person, Part 2, he revealed to his father that he was, in fact, deeply hurting because of his parents' separation, and helped his father to realize that divorce was not the answer to his parents' problems. After the reconciliation of his parents, David's relationship with his family was (presumably) restored.
David's younger sister is Mandy, and his parents are Rachel and Stephen Straussberg. Upon his sister's marriage, Trent DeWhite will be his brother-in-law, and he will have one grandnephew, Brandon, and a grandniece.