Spoiling the finale on purpose is a tiny cruelty that tells everyone how you’d handle bigger power.

Taking something from someone purely because you can is a small demonstration of a general policy. It costs nothing, gains nothing and ruins an evening they were looking forward to, which is exactly what makes it informative to everyone watching. People file it away without mentioning it, and they recall it later when something larger is at stake.

When you are holding something a person wants to discover for themselves, let them have it. That covers endings, surprises and news that is not yours to deliver. Ask first, and enjoy the odd pleasure of knowing and saying nothing.