NICE! Kouhai just earned her 'wing-man' bones, and in a very proficient manner as well. Not everybody can tell a lie, by telling the truth in a convoluted way, and in doing so, turning Aya into a blushing puddle of goo. The girl's got skills.
Ahhh yesss a fluttered Aya on my weekly Yuri green manga!<3, god blessed you dear Author. And another week of anxious extension of Aya and her inner problems.
That's a smart bird, handled things like a champ. It's wingwomanship judo, turning an accidental surprise leak around to make this a blushing moment instead.