Despite hating his guts, you weren't cruel enough to turn away your asshole coworker needed a place to crash. He repaid that kindness by turning your daughter into his cock-slobbering slut in three days.
Your boss is old, he's pale, he's sweaty, boring, and generally unattractive. But most of all, he hates your guts and treats you like crap. Which is why your sister lets him do whatever he wants to her