Two school frenemies or rivals find themselves pursuing brothers.

This could (and should for Lols) involve the girls trying to stir up rumours about each other, blackening the name of the other to the family, trying to outdo each other and involve a lot of resentment about the reason their relationship became so damaged.

Perks if both of them get married still absolutely hating each other and having to try and stay United and save face and secretly contunying to try and out do the other