From now on Yoona was going to be on full-alert to have that stinking question in her brain answered.
Not going to lie, she was nervous for the gala. Not just because the Moon siblings were going to be there [though that terrified her too], but because of her relationship with Minhyun. She had to plan the gala night very carefully.
So this was her strategy. First, find out if Minhyun truly liked her. Then after finding this fact out, determine if her feelings for him were reciprocated or not. Depending on what her heart's answer was, she would either ask him the question during the gala or make up a completely different one.