A la caza de marido = The Pursuit of Marriage (Bolsillo (terciopelo))

Cassandra Effington is one of the most delicious debutantes to ever waltz across a London ballroom. But while her identical twin sister Delia is now wed, Cassandra is still unclaimed, and everyone agrees her standards are entirely too high. So how could she possibly lose a most unseemly wager with the handsome, scandalous Viscount Berkley? The proposition: She will find him an ideal bride well before he finds her the perfect match. But Lord Berkley intends to be very hard to please. He's already chosen the right woman, and no lady Cassandra puts forward to him will be perfect enough save the luscious Cassandra herself. And he'll do whatever it takes to make certain no gentleman he introduces her to is enticing enough, until she realizes that the perfect object in her pursuit of marriage is none other than the viscount himself.