Could someone explain why the girlfriend from chubbi-kun suddenly got angry? (￣∇￣")

She wasn't angry. Embarrassed at the toast.

Oh thanks!!!! (⌒▽⌒)
Well it was a bit cheesy but still cute so ... it makes sense to be embarrassed at the toast.
⁄(⁄ ⁄·⁄ω⁄·⁄ ⁄)⁄