My friend keeps spoiling a show for me what do I do

I have wanted to watch this show for years, and once I FINALLY do, it gets SPOILED LIKE ROTTEN MILK. I have had beef with this dude, and every time I ask him to stop POLITELY, he just keeps doing it. I dont feel like I can be stern about it, either, since its just a show. Either way, it is a kind of shitty thing to do.