I feel I’m wrong but

I think they might be step brothers?

Hope not. Probably just similar looks cause author has similar looks ML (and another ML for second couple) in K’s secret.

I dunno he has a similar look I think it’s blood related?

Maybe? But he see,s like he hates the ml even before he met the uke tbh. Like he knows him prior

I don’t know if he hates ML strongly, but it does seem like he knows ML prior. But why would a dad hit on his son’s crush?