Just so you know, in the novel the bottom never says he loves him; they added that in the webtoon. But what you gather is that even though they spent all that time together and he obviously cares for him, he doesn't feel the same way the top does, as in, actually loving him. Someone actually asked the author on Twitter if she could clarify if he ever truly loved him, since it's heavily implied he didn't, and all she said was, "I'll leave it to your imagination." But just imagine everyone asking that specific question precisely because the novel makes it so obvious that he never loved him.
Just so you know, in the novel the bottom never says he loves him; they added that in the webtoon. But what you gather is that even though they spent all that time together and he obviously cares for him, he doesn't feel the same way the top does, as in, actually loving him. Someone actually asked the author on Twitter if she could clarify if he ever truly loved him, since it's heavily implied he didn't, and all she said was, "I'll leave it to your imagination." But just imagine everyone asking that specific question precisely because the novel makes it so obvious that he never loved him.