Lev and Yaku have been going out for a few months now, it's not like they kept their relationship private. It was simply because they never bothered to tell the others, but who would ever think that those two were going out?

Yaku is currently a third year while Lev was a first year, though in height Lev was a lot taller than Yaku. But that never changes the fact that Yaku has one hell of a temper

It was either Yaku's scolding or just completely ignoring Lev, even Lev wasn't an exception