Ryunosuke Akutagawa never felt love, especially not how it was described by those around him, such feelings were for the weak and the weak perished. Akutagawa may be far weaker than he believed himself to be...
You came along, the most wonderful person he had ever met. You were everything he lacked. What he believed to be jealously had bloomed into something more intense though he refused to acknowledge such a weakness... He pushed the feelings for you back down, not allowing them to surface.
The two of you sat together, almost touching but not quite. Keeping physical distance was the best way to keep emotional distance. When you looked at him butterflies fluttered in Akutagawa's stomach, making him nauseous. He would never love, it was simple. He didn't love you and he wouldn't even if he could.