A Spinster by the Sea. The Siren's Retreat Novellas, #3

Heiress Anne Baxter seeks a repairing lease by the sea after she's left standing at the altar for the second time. To her utter mortification, the best man, Augustus, Duke of Tindale, has been invited to a house party at a nearby estate, and comes upon Anne trying to enjoy some solitude along the shore. Augustus believes Anne is far better off without the buffoon who jilted her, but knows polite society will hold the lady accountable for the failed wedding, .
weddings, rather. He proposes to show Anne marked attention at the house party, in hopes that a ducal suitor will prove to the gossips just how lovely Anne is. Alas for Augustus's brilliant scheme, the best laid plans of dukes and damsels, oft go awry!