[ From the books he's read, Megumi knows much more about their physiology and behaviours than your typical teen. While the typical teenage alpha would be bumbling through their rut or driven recklessly crazy at the first whiff of an omega in heat, Megumi remains painfully aware and - to his best ability - self-contained. Silent, observant, and keeping his urges in tow. He can see his friend engaging in that nesting behaviour already, and that only confirms his suspicions. It's too late to take suppressants at this stage in time, however. The only solution that Yuji has would be to ride it out somehow.

He's trying to be the calm and dependable one, but he would be lying to himself if the sight of the other boy building a cozy nest for himself doesn't stir him up with those
animalistic urges. It's crazy; they're only fifteen, and in no position to even consider having a child together. Still, they wouldn't be instincts if they had conscious thought to them. An omega nests in preparation for their pups, after all. ]

Of course our sensei told you nothing at all. [ No surprise there. Megumi clicks his tongue. Now he's left with the burden of explaining this very awkward and embarrassing thing, when he's hardly in the state to be thinking logically. ]

You're in your breeding season. [ Might as well just be curt about it, even if it's so vulgar to say. ] You must have noticed yourself feeling worked up, right?