Please tell me somebody remembers this movie/show from I think the 80s or 90s.

OK – I think this was from the last century. A teenager (maybe a teenage couple) were being lectured to by an older person (maybe a parent) about the dangers of going to a high school party. He starts showing a slide show to them which says something like, “First, Mr. Drinky Thing shows up. Then, Mr. Smoky Thing – then, Mr. CRAZY Smoky Thing!” The picture he’s showing at that time is a fat joint. I think he ends his speech by saying, “The next thing you know, there’s a MURDER!” Please tell me somebody remembers this.