They were a comedy team, like a teenage Abbott and Costello or Jerry Lewis and Dean Martin. Kenan, the hefty "straight man," occasionally liked girls -- far less often than the tongue-lolling girl-watchers of other teencoms -- but Kel, the dimwitted "stooge" (left), never. His physical attraction to Kenan was rather obvious, like Jerry Lewis's to Dean Martin forty years before, with frequent hugs, soulful gazes, complements, and innuendos.
In the two-part "Bye, Bye, Kenan" (1997-8), Kenan's Dad gets a job as a forest ranger in Montana, forcing the two to split up. They try to sabotage the job to stay together.
In later episodes, they behaved more overtly like romantic partners.
In "The Honeymoon's Over" (1999), they appear on a game show as a newlywed couple, with Kel in drag.
The duo had rather a nasty breakup; in 2012, Kel told TMZ that "Kenan doesn't want to be seen with me in any form of media, or even have my name mentioned around him."
Maybe it has to do with the direction the actors' careers were taking?
In the episode I saw of the Nickelodeon animated series Wild Grinders (2012-13), about preteen skate boarders, his character, J.J., was shown briefly holding hands with the Goth boy Emo Cries.
Currently Kel is starring in the CW digital series Stupid Hype, as the flamboyant rival to break dancer turned rapper Hype (Wilson Bethel).