It was a lie

Sure enough, after that encounter, Hae-won started avoiding Woo-Bin, claiming him to be a creep. And a relentless Woo-Bin followed after him regardless of how he kept trying to avoid him. 

From the cafeteria to the school fields to any other place Woo-Bin was able to go, he followed Hae-won everywhere.

At the end of the week, a tired Hae-won turned to Woo-Bin with anger in his eyes.

"Will you just stop it?" He fired at him.

"Stop what?"

"Stop following me. Stop going everywhere I go and doing everything I do. It's annoying." His outburst was supposed to silence Woo-Bin but surprisingly, he smiled and said,

"I'm not following you." This ticked Hae-won and he turned around to leave. Woo-Bin watched him and chuckled.

Toying with Hae-won was fun.

Even if he said he wasn't following him, he still followed the same route Hae-won was taking while being very obvious about it.