The brother is a proper psycho. Not a cutesy weirdo, but a proper sociopath. Like he doesn't even think like a human being, and he really believes he is the good caring sinbling (like he pushed Chase under a car when Chase didn'twant to go to school, because clearly being hospitalised excuses you from school). Their family is so fucked up, when the youngest child was an omega, parents fled from their alpha sons just in case.
ikr? and he specifically said it was "for his sake" so like does the body need to both rid of the pheromones AND think it's slept with someone or else it will combust??? i don't get it at all. he goes on to say that it's so that chase would release his pheromones, but how do the two connect? if i thought that i spent the night with a dog i'd rather never release my pheromones and let it melt my brain than risk my instincts reaching for whatever is most close. then again, he probably doesn't gaf and is just spouting bullshit when in reality he just wanted to fuck his brother up
the injections to extract pheromones (i think that's what you meant) are unhealthy. if i'd have to guess it probably has something to do with natural bodily cycles that align with a heat/rut period. one of them is likely lowering fertility which tends to be important in this kind of setting (rich family/chaebol settings)
Not for fun. The pheromones here are harmful to the extent that it destroyed their father's brain n he almost died. Same thing could happen to Chase if he would continue to taking injections. But chase was rigid that he won't sleep with anyone so Grayson tried to scare him so that he would start using the natural and safe method of extraction.

Wait I don't understand, why did the brother tell Chase he did it with a dog instead of telling him he injected pheromones? Just for fun to traumatise his brother?? Whats wrong with injecting pheromones??