Characters A and B are in love with each other, but both of them also love C, so they think a poly relationship would be the ideal option, assuming that they can get C into it. C has feelings for A but not for B but pretends to be into them both because he/she figures that's the only way of getting to be with A.

A=Taiwan
B=Romano
C=Seychelles

Request and (ongoing) fill:
http://hetalia-kink.dreamwidth.org/82590.html?thread=510139038#cmt510139038