One and Only (A Niall Horan Fanfic)

A lot of people say it is impossible to be best friends with the opposite sex without having feelings for them. Well Niall and Alexandria, or Alex as everyone called her, have been friends for what seems like ever. Their friendship is one of the strongest. But what will happen when Alex gets engaged. Will they realize that maybe what people say is true? That the opposite sex can not be friends without catching feelings.