My brothers best mate (Liam fanfic ft. Louis and Larry)

Imagine going from shy girl in the back of the room to dating your brothers best mate Liam Payne. What would you do?
Hi I'm Riley Horan. Yeah that's right Horan, as in Niall Horan. I'm his little sister. I used to travel the world with him a lot when One Direction first got started. That was before I met Josh, my boyfriend. Niall says he's manipulative but I say he's just jealous. He hates the idea of his baby sister having a boyfriend. It's probably part of the reason for me being forced into going on tour with him for the first time in almost two years. That or he actually misses me after pushing me away and never coming home. Ether way this should be interesting...

Or the one where Riley and her brother Niall are best friends since the day she was born. Doing everything together, attached at the hip until one day she starts dating a not so friendly guy. What will happen when old feelings for Nialls best mate, Liam, start to pop up when she is forced to go on tour after not seeing them for a year and a half? Will Niall let his over-protectiveness get in the way or will he let Riley be happy?