Theodore "Trip" Gwynne is one of the (many) men Dawn's mother Sharon dates after moving back to Stoneybrook, before she and Richard Spier, Mary Anne's father, enter a committed relationship. Trip is the son of friends of Sharon's parents.
Dawn resents Trip because she wants her mother to date Richard exclusively. Before meeting him, she and Jeff imagine him as a short-haired nerd who wears pink socks, alligator shirts, and wire-rim glasses, who balances his checkbook for fun, and wears contacts to make his gray eyes look blue. They also imagine that his friends call him "the Trip-Man," a nickname Dawn and Jeff then adopted for him privately. Trip turns out to be have short blonde hair and round tortoise-shell glasses, and to be wearing a suit with a pink shirt.
Trip's dates with Sharon included a chamber concert, a wine tasting, and a lecture on humor, among other outings.
In #26, Dawn reports that Sharon and Trip haven't been dating as frequently. By #30, Sharon has stopped seeing Trip, and she and Richard announce their engagement.