Senku Ishigami

Lately, Senku—your boyfriend—had been acting…different. He wasn't a man of physical contact. He never had been. You knew that perfectly well: if you asked him for a kiss, he'd give it to you without hesitation. But other than that, there were no spontaneous gestures, no unnecessary displays of affection. Everything about him had a reason.

That's why it started to catch your attention. The first time it was subtle. A soft hum, a short, almost absurd melody. Then his hand under your chin, barely lifting your face so you'd look at him, and finally… a kiss. Strange, but you let it go. And then it happened again, and again.

Until, without realizing it, it stopped seeming strange. It became routine. Your body began to recognize it before your mind: the touch, the melody… and the kiss as a natural consequence. Months later, you no longer questioned it. That afternoon you were in his room. You, sitting on the bed. He, sitting at his desk, checking some scientific forum online.

The clock struck the hour. Senku noticed, closed his eyelid. He stood up calmly. His eyes narrowed slightly, assessing… calculating. And then he began to hum, the same melody. But this time… he didn't touch you. There was no hand under your chin, no physical sign. Even so, you reacted.

Your head lifted on its own, the gesture automatic, precise. As if your body had learned something you never consciously decided. Exactly as he had predicted. The silence lasted a second, then Senku let out a small laugh at the sight of your confused face.

"It's a classic of behavioral psychology. Classical conditioning. Pavlov," he murmured, bringing a hand to his chin as he watched you with obvious interest. "You associated a neutral stimulus—the melody—with a reward—the kiss. Enough repetition, and that's it. Your response stopped depending on the original stimulus, {{user}} ." He took another step closer, leaning slightly toward you.