"Padfoot."
Sirius looked up to see Remus put his book aside. They were in the living room. Sirius was kneeling by Remus' feet, completely naked except for a black collar. It was one of the first things Remus had bought for him and he adored it. It was simple, leather and cushioned with velvet. There were charms added; one made it change with him every time he would shift into his dog form, as well as self-cleaners and glamours so he could wear it all the time without anyone else noticing it.
"Master?"
"Come here," Remus ordered as he spread his legs.
Sirius eagerly complied and quickly moved to sit back on his hunches between his Master's legs. He looked up with hopeful eyes. Remus smiled as he ran his fingers through his sub's soft hair.
"Go on, then. Show me how good your mouth is."
Sirius didn't need to be told twice as he quickly undid his Master's trousers and pulled out a heavy dick. To him, it was the most beautiful dick out there. He could go on for hours just talking about it. It was thick, his hand barely being able to circle it and long. The mushroom head had pushed out of it's foreskin and had an angry shade of pink. There was also a drop of moisture starting to pool on the slit. There was a sudden tug that reminded Sirius of his task. He quickly lowered his head to take his Master into his mouth.
Remus relaxed and sank back into the couch. There was no foreplay or teasing. Sirius had dove right in, easily swallowing him down into his throat. He still struggled to swirl his tongue around while sucking him down but that didn't stop him from trying. Remus let his hand guide the speed; he wanted to enjoy this and was in no rush to come yet. After a few minutes, Remus didn't allow his sub to pull back up.
Sirius shifted a bit at this new demand. Understanding, he readjusted his breathing and concentrated on swallowing. His head was lowered inch by inch until his nose reached the end of the nest of his Master's pubic hair. He breathed in the musk as he continued to flex his throat muscles. His eyes started to water and found it harder to keep his jaw slack enough to avoid any teeth getting in the way. Instinctively he felt himself begin to fight back but was held down.
"Easy. Just breathe. That's it, relax. Such a good dog."
Good dog. I'm a good dog. Sirius closed his eyes, letting himself go into the comforting fog of endorphins that started to spread within him. His body started to buzz. There was nothing except his Master. Master was humming in approval. Master was petting him, praising him. All that existed was pleasing his Master by swallowing him down. Soon, he was reward. Master was groaning as his thick seed started to drip down his throat. A burst of happiness erupted throughout his body. He had pleased his Master. When Master had finished rewarding him, his head was being lifted so Master could lean forward. Another reward! Master had rewarded him again by kissing him. Eagerly, Sirius kissed back, cherishing the feel and taste of his Master's lips and tongue.
"You did well. Good dog."