Derek is a motorcyclist who Teddy dated for a while.
Derek loves motorcycles and motorcycle jackets. He also writes poetry and doesn't seem to care when he gets dumped.
Derek is tall and has brown hair
Derek and Teddy go out for sometime. Derek is loyal to Teddy and very "understanding". In The Break Up, Teddy dumps him.
Derek appears to be a classic 50's style biker, but without the dialect of that time period. This can be assumed by his haircut and by his attire.