What is it about the brother’s best friend and his little sister hooking up that is so irresistible? It's one of the most popular themes in romance, appearing over and over again.
Perhaps the main appeal is there's a sort of built-in chemistry that naturally exists between these two people who have denied what they want, sometimes for years. He wants to protect her like a brother. but feels something so much stronger and not very brotherly towards her. There are endless possibilities resulting from this chemistry. And whether it's a noble hero who's trying to keep the brothers' code of honor, or the heroine whose feelings of fondness toward her brother's best friend have grown into an abiding romantic love, the combination of these qualities and degree of urgency in giving in and crossing the line are what makes these stories our favorite.
In Samantha Young's On Dublin Street series, Adam and Ellie's story is a simmering, quiet tale told in the midst of Braden and Joss's big love, but it's not at all unexpected. In fact, we hope for their happy ending just as much. But between years of friendship and the fear of ruining that, along with worry about Braden's disapproval, misunderstanding and frustration have stood in the way. Though it takes a life-or-death crisis to finally bring these two together, Young throws the trope on its head when it's easy-going Braden who roots for Adam and Ellie most of all. They're one of those couples who we just know is meant to be because once they allow it, everything's easy, and two such sweet people deserve nothing less.