Summary: Kaiba won't share. He won't share Yuugi with anyone. Rivalshipping.
Yuugi rocked back and forth in his chair, his feet on the desk in front of him. He watched all the other students socializing around him. He turned behind him to see Kaiba, his face buried in a book. Kaiba looked up when a gruff voice addressed Yuugi.
"Are you coming to the basketball game tonight?" asked the boy. "N-no. I don't really like sports." Yuugi said. The boy leaned on Yuugi's desk flirtatiously. "Oh, come on, Yuugi-kun. You should come see me play tonight." he said. "I'm sure you'd play well, but no, I'm not coming." said Yuugi. Kaiba watched the boy lean in to kiss Yuugi on the cheek. His face burned in fury, his fists balled up, and his teeth grit angrily.
Soon, the other students left for who knows what, leaving Kaiba and Yuugi alone in class. "I saw what he did, Yuugi." Kaiba said, closing his book. Yuugi shrugged. "Didn't that bother you?" Kaiba asked. "Not really. It's just a kiss." Yuugi said. Kaiba moved to the desk beside him. "It's not just a kiss!" he cried. "Why is this bothering you!? You're acting jealous!" Yuugi screamed. "Maybe I am!" Kaiba exclaimed.
They fell silent, both blushing profusely for their own reasons. "Why are you jealous, Kaiba-kun?" Yuugi asked quietly. "I won't share you with anyone." said Kaiba. "Share me?" asked Yuugi. "Yes. Share you. I refuse." Kaiba said, closing the distance. In fact, they had gotten so close that Yuugi was straddling Kaiba's lap. "Kaiba-kun..." Yuugi panted. Kaiba began to place kisses around Yuugi's neck and shoulders. He unbuttoned a few buttons on Yuugi's shirt to kiss around his shoulders better.
"Ah, Kaiba-kun...no..." Yuugi moaned. "I need to mark you, to let people know that you're mine." Kaiba said. "You'll be no better than that guy!" Yuugi cried. "Why? What's the matter? It's 'just a kiss', isn't it?" Kaiba teased. Yuugi couldn't say anything. Kaiba was absolutely right. "Go ahead. Go ahead and mark me." Yuugi said. Kaiba smirked and latched his mouth to Yuugi's neck.
"Ahh..." Yuugi moaned. After a few more bites, sucks, and kisses, Kaiba left plenty of passion bites around Yuugi's neck, and moved to mark his shoulders. "My Jii-chan is going to kill me for all of these bruises." Yuugi moaned. "I'll explain it to him." Kaiba mumbled, biting down on Yuugi's shoulder.
When all was said and done, Yuugi 's neck and shoulders were covered in little finely placed passion bites. He readjusted his shirt. "Not even my collar will hide all of these hickeys." he lamented. Kaiba smiled. "I think you look better with those bruises." he teased. Yuugi rolled his eyes. "Hey, just be glad we're at school. If we were elsewhere, I'd have taken you on the spot." Kaiba said.
Yuugi ran his fingers over them. "It'll take forever for these things to go away." Kaiba pulled him closer against his body, kissing Yuugi on the cheek. "And once they fade away, I'll place more." he said. "Oh..." Yuugi moaned. "You're mine, Yuugi. I won't share you. You're always mine."