I think for Na-eun case it's not a crush anymore, more like an admiration. The one that I see as clear is just Moojin, ohhhh and Rose also clearly doesn't like MC that way, she might think she is but we know that's not true. Beside the MC doesn't look like he care ahahahaha
Hmm not exactly since this is how other MCs react with their siblings/nephew, they're usually the sister and mother though. These stories usually kill off the male family lmao
But I can agree with you to some extent, given how many yaoi/bl this site has, it's bound to cause brainrot haha
"totally unexpected"