Responses

From my understanding, the stronger an individual's feeling for someone the stronger their pheromones. So basically those two idiots like each other so much their scent got too strong for their current medicine to repress. It's also the reason why the uke asked the seme if he smelled anything when they were fighting, presumely because if the seme hated/didn't like the uke anymore he wouldn't be able to smell anything/the pheromones wouldn't affect him.
I read this manga a couple times but i still don't get Chapter 5 page 180-181