Grammar nazi AU!

A has a really bad case of the grammar nazis, and hates reading B's texts with terrible spelling and grammar, so always moans to B about it.

Friendship, siblings or a lovers tease, it works for this.

I imagine anything with Seto in it since he's so... Seto

Or if you like the fandom, Armin, since he's so... Armin

Whatever, but this one would be all kinds of cute and funny!