'Forever Betrothed, Never the Bride' by Christi Caldwell is book one in the "Scandalous Seasons" series. This is the story of Lady Emmaline Fitzhugh and Lord Drake. Emmaline and Drake have been betrothed since they were really young. Their fathers were friends and had set their betrothed up, but since then Emmaline father has died. Drake went off War after being upset about being forced into a betrothed. When he came back he was a changed man...the war had been very tragic and horrifying to him. Causing him to have nightmares and to 'zone out' somewhat. So since coming back he has avoided marrying Emmaline which is making her into a spinster. Emmaline goes forth to try and force his hand into marrying her or to either let her go. But the more they start to interact the more they start to have actually feelings.
Once I read this book I had to read the whole series in a marathon read!