Sirius had always had a passion for Muggle music. One day, left alone again, he decided to do some good old-fashioned cleaning. He put on an apron (frilly and pink, as no one would see him), grabbed some Muggle cleaning supplies (broom, mop, sprays, and the like), and put on some music. Because what fun is cleaning if you can't do it to Cher?
He was almost done, when "Gypsies, Tramps and Thieves" came on. He gave a scream of transcendental glee (something else he would never do if not alone) and decided his current cleaning utensil, a feather duster, would make the perfect microphone.
"I was born in the wagon of a traveling show…"
Now, Sirius was an all-or-nothing person. Nothing he did was half-hearted, whether it be loving, cleaning, or dancing around the living room wearing a frilly pink apron pretending he was a famous gay icon.
Thus, he did not notice Remus standing in the doorway with a bemused smile on his face.
"Papa would do whatever he couuuuld!' Enter the Diva Hand. You know that hand. Held out dramatically as the singer belts out some emphasized bit. Damn, Sirius thought, I was made for this.
"Gypsies, tramps and thieves! We'd hear it from the people of the town…" Now he started getting really into it, gyrating around the room as he sang. Remus contemplated getting a camera.
"Three months later I'm a gal in trouble and I haven't seen him for a whiiiiiiile…" Oh, priceless.
When he reached the end, Sirius flopped down onto the couch with an exhausted "…and I'm spent."
Remus burst into laughter and Sirius noticed, finally, that he was there.
"Psh, you wish you were that good."
"Oh love." Remus said, still chuckling, as he walked over to the CD player and changed the track to "Half-breed". "My turn."