The Best of Friends by Sarah M. Eden

Daria Mullins just accomplished the seemingly impossible: she successfully convinced her parents to grant her one final London Season. Though their concession comes with certain expectations, Daria is determined to enjoy every moment alongside her dear friends, the Huntresses, as they make their annual foray into the Marriage Mart.

Toss Comstock has no interest in marriage. His only purpose in London is to enjoy his Bachelor Season before he’s forced to follow whatever path his elder brother deems best. But his plans are quickly turned upside down when he strikes a bargain with the lovely Miss Mullins at the Debenham Ball. The longtime acquaintances discover that they share the maddening affliction of familial pressures, leading them to hatch an outlandish scheme: they will engage in a friendly competition. Whoever participates in the most activities their family would disapprove of will be crowned the winner. But amid the fun and games, Daria and Toss never imagined that true love would become the ultimate prize.