Chanyeol doesn't really think about Baekhyun being a close friend. A casual classmate maybe, but definitely not someone he will spend time with. The guy is simply reckless, impulsive and all sorts of confusing and he draws the line at people who only throw him into confusion.

So when Baekhyun confessed to him in a very unusual way, he did what he thought was the best. He rejected him.