Is he really though? The way I see this is he purposely misconstrue everything because he is in deep denial, not that he is dense or stupid. He knows perfectly well, but still hopes it isn't true so he does his best to steer Jaekyoung away before things get out of hand. It hasn't been fully explored why he doesn't want to accept Jaekyoung, but there are plenty implication such as age gap, insecurities because Jaekyoung has what he doesn't have, status gap, him being the manager, and so on.
"hopes it isn't true" is literally denial.
"It hasn't been fully explored why doesn't want to accept jaekyung" - you writing this is also you accepting that he is denial of his own feelings.
Denial inherently means that he knows or understands that he too is attracted but he doesn't want to acknowledge or admit it.
He's the older one but not the wiser one. I actually don't like how his character has been written. He's been written down like he doesn't comprehend social cues & doesn't understand emotions like love. To sit & misconstrue EVERYTHING about a person he clearly cares for, is so stupid.