BtVS by Joss Whedon and Mutant Enemy. Golden Girls by Harris of NBC and, partially, by Joss' father, Tom.
Post-Chosen. Set sometime after 'All That Jazz', using the version of Michael that was seen in that episode.
"Hi mom," said Michael when Dorothy answered the door. He entered the house and threw his arms around her. "I missed you."
"Me too, son, but you still can't live here. Don't tell me. The band dissolved and you need money."
"Nothing of the sort, mom. I have a new job, so I'm just in town to tie up a few loose ends."
"That's wonderful. What do you do?"
"I train super-powered young girls to fight the powers of darkness."
"Right. You know, I think I'm going to sit down," Dorothy said, frowning as she did so. "So, you've joined a cult?"
"Nope. It's a network of private schools across the country, dedicated to helping people fight the good fight. I'm even learning some basic spells myself."
"So, it's a cult... Honey, magic isn't real. You certainly can't do anything with it."
"Sure I can," Michael said, eying an empty cup. "Lagoena," he intoned and the cup filled up with water.
"Great. That's it, I'm dreaming. I never should have let Rose talk me into having chocolate and marshmallow pizza for dessert."
"No, mom, it's real. I didn't believe it either until I had to stake a vampire outside a club one night. Our guitarist admired my technique and put me in touch with a few people-"
"Hey, are you guys talking about magic?" asked Rose Nylund as she entered the room through the kitchen. "That's wonderful, I've been waiting to tell supernatural stories for years but I didn't think anyone would believe me. You know, my hometown of Saint Olaf was named after a giant troll that terrorized the region. Of course, that was back in Norway, years before everybody in the town was teleported to Minnesota without even the clothes on their backs. Let me tell you, it was a very cold winter that year and if hadn't been for-"
"That's it," Dorothy yelled, throwing her hand up in the air. "I'm going into the kitchen for a strong drink and when I come back I want everyone to be making sense."
"So," Michael asked Rose, who'd quite lost the thread of her story. "Why'd you call the troll a saint?"
"Well, even though he ate quite a few babies in the village, one of them was the son of the World Serpent, Jorgi-Mundr. The snake had been surrounding a castle, trapping everyone inside for years and when he was eaten everyone came out and thanked Olaf, as they were quite grateful and very smelly."
"That's ridiculous, Rose," said Dorothy as she re-entered the room. "How could anyone, even a giant troll, eat a snake that big?"
"It was only six feet in length, Dorothy. It just happened to be a very small castle."
"Gah! Michael, I blame you for setting her off like this. Why are you even talking to me about your life? Shouldn't it be, you know, some kind of a secret?"
"This isn't my idea. Apparently I'm part-demon and they need a thorough background check before I can be a full-time Watcher."
"Oh," Rose said happily. "You mean like that Mr. Nielsen who always sends his report to the networks every week?"
"No, Rose," corrected Dorothy. "Nielsen's just the name of the company he founded, he doesn't actually... Why am I explaining this to a woman who can't tell the difference between a blue light special and a blue plate special? Mom! Come in here!"
"Did someone call me?" asked Sophia Petrillo as she swept into the room. "Michael! How's my favorite grandson? You know, you could have told me he was here."
"Your grandson," Dorothy said, drawing out the word. "Wants to know if you're a demon."
"Honey," Sophia answered with a smile. "I thought you'd never ask. Picture it! Sicily, 20 B.C. I was a young spawn, newly hatched and as cute as a bug in a rug, for good reason..."
Not wanting to hear any more, Dorothy stood up, walked over to a wall and gently banged her head against it until the end of the story.