Beauty & the Duke by Nadine Millard

Isabelle Carlton has loved the boy next door for as long as she can remember.
Now they’re both grown up, their lives could not be more different; Mathew is a studious, serious duke, and Isabelle a social butterfly and the darling of the ton.
But Isabelle still wants Mathew, and she has no intention of letting him go.
So, all she has to do is make him fall desperately in love with her. And who better to help than the man himself?

Mathew Rourke hates everything about the shallow world of the ton, and the people who play its foolish game.
And none of them play it more than Isabelle Carlton.
When Isabelle enlists Mathew’s help to catch herself a husband, he reluctantly agrees.
After all, when has he ever been able to tell her no?