Niall hates Harry, he is obnoxious and enjoys making Niall's life a living hell. But Harry can't help but feel intrigued by the way Niall makes him feel and he has no other way of getting a reaction from him because their forced to be step-Brothers. Harry craves Niall's reaction in every little thing he does and Niall can't help but give him one, so what happens when these two go on a one month family trip to four different countries. They're forced to share a room together and what will happen when they can't hold back on the sexual tension? Will Niall eventually give into Harry? Or will they continue to hate each other till the day they die? Contains smut and very explicit language. 13+