Harlequin HQN romance.

"This is a reissue of reader favorite A WEDDING RING PROMISE" -- from author's web page

"In her youth, Molly Anderson couldn't help crushing on gorgeous bad boy Dylan Black-- even though he only had eyes for her older sister. When things didn't work out between them, he said goodbye to Molly as well, vowing they'd have a great adventure when she grew up. Years later, dumped by her fiancé just before Christmas, she's finally ready to take Dylan up on his promise. A guarded Dylan always had a weakness for Molly, and when she waltzes back into his life-- grown-up and gorgeous-- he's stunned. So why not whisk her away for some no-strings-attached fun. Laughter-filled days and late-night kisses are changing Molly's life, for good. The only gift she truly wants now is Dylan's love, but when he discovers the secret she's been keeping, she may lose him again-- this time forever" -- summary copied from ebook record