My prediction:
Yokoe is going to get restless throughout the date and stress eat. Later on when she tries to confess she'll do it before the fireworks go off ((because she's semi-smart like that)) but after eating so much she'll get major gas and fart so loud Kei can't hear the confession.
I think it's a bit odd but would definitely happen- That or the author actually let's her confess so let's hope (・ωー)~☆