" Let me say that she's 16 and her room would probably qualify as a biological hazard."
Ha! Just tell her it's OK for her boyfriend to visit her in her bedroom and watch her clean up her act. Of course, that's not a good idea, for other reasons, but it'd work.
Ha!! At 16 I was allowed to watch a movie in my room with my boyfriend, but the light had to be on and the door wide open. There was no deviation from the rules. Of course, my room was never a pigsty, and no one ever crossed my dad.