I doubt Kiffin screwed Saban's daughter. How much of a moron would he and she have to be to do that?
I also doubt that Kiffin would get fired for screwing a booster's wife. Who gives a shit? There's plenty of money at Alabama.
Since the rumors are sexual in nature, I think it's easy to assume that Kiffin is plowing coeds in his apartment. Layla doesn't live in Tuscaloosa, so I'm sure Lane's been on the prowl for a while.