Sworn Promises by Jill Monroe

She’s his best friend’s sister.
He’s the guy who never looked twice.
Then Vegas happened.

Future astronomer Piper Larson is happy to plan her brother’s quickie wedding. Until Ryan Bullock signs on as her partner. She’s secretly fantasized about the navel rescue swimmer since moment one. But the sexy, real life hero remains forever out of her orbit.

Ryan lives and breathes loyalty. His buddy’s little sister? One hundred percent off limits. But he’s never craved a woman as much as the sunny Piper. On his long, lonely deployments, he thinks of the forbidden beauty with stars in her eyes and nothing else.

Now, as they traverse Sin City for the most romantic locales, all bets are off.

People say what happens in Vegas stays in Vegas…
…but what if it doesn’t?