Ok, I was really confused but I think I figured it out:
Boss overhears hoobae talking to friend worried about our main character. They walk in the same direction, but boss stops at a convenience store, while hoobae goes straight to MC’s place.
Hoobae gets tempted by the pheromones and starts taking advantage of MC. MC hallucinates hoobae and thinks it’s boss.
Boss arrives at MC’s place, stops hoobae and kicks him out. MC begs boss to keep going, and he starts to.
Friend arrives to MC’s place, interrupting boss. Boss opens door and lets him in.
MC eventually falls asleep, by which time both friend and hoobae are gone. When he wakes up, boss gives MC the medicine he bought earlier