Sebastian is a new student at Charles Barklay. He is a British exchange student who is also a homosexual. He became Kenny's new crush when he came to the school, but was asked out by Stuart, when coming out of the closet before he could. He appeared in the episode The Real Prom.
In the episode The Real Halloween, which took place a year after the events of Sebastian's debut, Kenny said that he and Allison were the only two gays in the school, implying that Sebastian must have left the school again.
- "Sebastian" is one of Kenny's middle names, which is a little connection as to why Kenny was in love with Sebastian.