Blaise gazed out one of the Slytherin windows without expression. The dungeon windows looked directly into the Forbidden Forest. He jumped when he saw someone run past. He squinted and realized that the figure and gait belonged to the beloved Boy-Who-Lived. He was amazed sometimes by that child who stood up to Voldemort and the Ministry and, on occasion, Dumbledore. Rumor had it that the Boy-Who-Lived had trashed Dumbledore's office. Several times, now, in fact.
Blaise glanced around and opened the window. Slytherin windows were the only one you could really climb in and out of. He slid out like the proverbial snake and ran after Potter. He was startled when he came upon a clearing that Potter was resting in. "What are you doing?" he called.
Potter spun, wand drawn. He was obviously used to running, and Blaise nearly rolled his eyes. He squinted and sighed. "Zabini, what are you doing out here?" he asked.
"I was following you," Blaise said. He figured he didn't need to tell Potter for how long. "What are you doing out here?"
Potter's eyes narrowed in suspicion, and Blaise's heart leaped as he realized Potter didn't trust anyone. He'd seen the same look directed towards Potter's best friends' backs. "You need to leave," Potter said, not bothering to fill in the blanks with why.
So Blaise asked: "Why?"
"Because you won't like the results if you stay for very long," Potter said, looking around them.
"And you would?" Blaise asked, wrinkling his nose.
"More than you would, I imagine," Potter said.
Blaise heard a rustle and turned. His hair nearly stood on end when he saw the centaur enter the clearing. "Mars," the centaur greeted Harry. He looked at Blaise, eyes narrowed in similar suspicion as Potter's.
"Romanji," Potter greeted back.
"You brought another. This was not in our agreements," Romanji pointed out hostilely.
"It's not my fault. He, apparently, followed me," Potter said.
"He is an enemy?" Romanji asked.
Potter glanced at Blaise appraisingly. "I don't think so. I think he's just foolish," he said.
"The foolish never last long out here," Romanji said, raising his hand.
"But this one will," Potter intervened, standing before Blaise daringly. Romanji's hand fell anyway, nearly knocking Potter off his feet. He looked back up at the centaur bravely.
"You have taken a blow for this boy. He is your ally now," Romanji said. "We will allow his continued attendance.
"Yes, sir," Potter said quietly.
Other centaurs moved forward. Blaise jumped at the number of them there. There was at least a tribe. That never happened. Not for a human.
The centaurs turned to Blaise and looked at him. "Bow," Potter hissed.
Blaise followed Potter's order without question. The centaurs watched.
"He is on equal standing with you?" Romanji asked.
"Yes. He is my peer in school," Potter said.
"But is he elsewhere?" Romanji asked.
"Yes," Potter said.
The centaurs murmured for a moment. Romanji eyed Potter levelly. "Then he is your spouse?" he asked.
"No," Potter said. Blaise could hear the frown in his voice.
"You claimed him as your equal in all aspects. Only a spouse may claim that right," Romanji said.
Potter was silent a moment. "He is better than me at some things and worse at others," he said slowly. "It is the same with all humans."
"Is he to stay here? We cannot let him live if he is not your spouse," Romanji said.
Blaise's hands grabbed Potter's cloak with fear. He hadn't anticipated this when he followed the boy. Potter took his hand carefully. After a moment's pause, he said, "How do we marry according to your people?"
"An exchange. You may exchange anything you like, but be sure it is important to both of you," Romanji said.
Potter turned to look at Blaise, appearing somewhere between embarrassed and determined. "Would you prefer this to death?" he asked softly.
Blaise nodded slowly. "Are you sure you can do this?" he asked quietly.
"I've done worse," Potter said wryly. "What do you think we should exchange?"
"Blood?" Blaise suggested after a moment.
Potter nodded, turning back to Romanji. "Will that work?" he asked.
Romanji watched Potter for a second before nodding. "It will do," he said "This is the most binding of vows."
Potter nodded. He gently pulled his hand from Blaise's and rolled up his sleeve. He looked to Blaise. "My blood was given to another but not willingly and with no return."
Blaise nodded quickly, having already pulled up his own sleeve. They bared their forearms to the centaurs. Romanji stepped closer and grasped their wrists. "For life and all death do ye of human blood bind yourselves by blood to one another. May life never run dry as doeth the river. May death never find those of your loins or ye yerselves. Thus I do make you mated for all time, never to be touched by age again," he said in an older accent. Two other centaurs approached and parted the skin on both boys' arms with silver knives.
Potter brought the seeping wound on Blaise's arm to his lips and kissed it with parted lips. Blaise found himself drawn to do the same to Potter's as the other boy drew himself up once more. The few drops of blood that brought into Blaise's mouth, he swallowed. Potter's ruby lips, colored with Blaise's own blood, met Blaise's in a soft, kind, loving kiss.
Potter looked over at Romanji. "I'm afraid we shall have to conclude this meeting some other time. I believe we are to consummate," he said. "I will take him to a private room in Hogwarts that I know of. Is that agreeable?"
The centaur watched Potter a moment before saying, "Because you are human, your consummation must be witnessed," almost apologetically.
A light blush fell across Potter's cheeks, but he nodded and turned to Blaise. He held out his arms. Blaise stepped into them, cupping Potter's face as he kissed the smaller boy. They very carefully undressed. Potter… Harry. They were married. Harry nuzzled Blaise's neck as he unbuttoned the silk shirt the Slytherin wore.
Harry submitted to Blaise easily and despite being watched, they found themselves enjoying the joining.