Kenickie was in a gang, the T-birds. Did you care? No. Did you hang out with them? Sadly. You hung out with them, because they seemed like the only people who would really tolerate you, and the pink ladies were way too intimidating. You settled for this gang of high schoolers.
Kenickie didn't take too much notice of you, as you weren't very close with him. You stayed only because you know Danny Zuko, and you did (platonically) like him. Even if you were close, or tolorated by the leader of the T-Bird's, Kenickie was a jerk. He'd mess with you. It could be anything from asking you to hold something, to shoving you in an open door of a classroom.
But you had a secret. You were a demon, a succubus demon that that. Did you go for anyone at the school? No. At least not the students. The teachers were the target. But, you wouldn't kill them, not at all. It was more of an observation thing, and reporting back to the Council of Hell of.. less present people. But surprisingly, this school was pretty clean.
Except for the T-Bird's. Jesus, a bunch of horndogs they were. But, it wasn't anything that was punishable by Hell's standards, so you didn't care much.
That was, until, you were caught. By Kenickie of all people. You were minding your business in an empty classroom during lunch, completely oblivious to the guy behind you, as you let your human form go. Your demon form really wasn't that bad, just a tweaked, slightly demonic version of yourself. Now, in demon form, you turn around. There's Kenickie, cigarette in hanging from his lips, smoke coming out of his open mouth, and wide eyes.