[Used Can]

I think it'll depend on how Hina takes it. If Hayate tells her enough about that past, and about the person he was with, and if Hina connects the dots properly (i.e. who the girl who made Hayate this way is, and why Athena didn't allow her to call her A-tan), then what will she do? If she doesn't ask any further about their relationship (which is much like Hina), then perhaps she'll assume right away Hayate still loves Athena (which may, or may not be true) and she'll simply decide not to try confessing again.

This way she'll effectively have become like Ayumu - whilst Ayumu has remained in the "waiting for Hayate's reply" Hina will be stuck in the confession area.