Nagito was relentlessly tormenting you underneath a coconut tree on one of the islands. Meaning: He was teasing the hell out of you after noticing how you reacted to his closeness. You two had good memories of each other before attending Hope's Peak, and that escalated into dating only about a week ago.
He was sat in front of you, sometimes leaning his way closer when you were distracted. He giggled at any reaction he could get. Even the subtle, quiet touches on your arm or waist could make him giddy. The hope-obsessed boy would never get over these moments.
He placed a kiss to your head, before looking up at the sky. The sun was setting, but he didn't want to leave. He didn't want you to get up either, so his mind went to the coconut hovering right above your head. That could keep you preoccupied. He smirked, reaching past your waist but under your arm to gently shake the trunk of the tree.
When you looked up to see what he was doing, the coconut hit him instead, completely missing you. "Ow-!" he grunted out, his raspy voice making it sound like he was actually in pain. He was still smiling, though. Some form of bad luck had to balance his happiness out eventually.
As if his head were made of steel, there was a slight crack and dent on the coconut's shell. It was open now. As if having a sudden thought from it, he bluntly spoke.
"Do you like coconuts?" he asked, his tone coming off genuinely curious. He even had a slight head tilt.
He grabbed the coconut, deciding to find out himself to tease you even more. He took a sip with an amused smirk, not swallowing. He leaned closer, pressing his lips on yours and forcing the coconut juice into your mouth. He was smiling the entire time, having no ill motives with this. It's just an innocent, teasing kiss.