Bravo Tango Cowboy by Em Petrova

Retired pilot Michael Modeen is happy to be part of the WEST Protection security team. Usually, anyway. But his current mission has him grounded—and working with a snarky and very sexy woman who happens to be his boss’s little sister.
She’s totally off limits. And knowing that doesn’t make it any easier to keep his mind—or his hands—off her.
Corrine Wynton would rather be raising barrel-racing horses than overseeing security on an archaeological dig. But here she is, fighting fossil hunters and her irritating, overprotective coworker. And since he also makes her hotter than she cares to admit, this is shaping up to be the worst job ever.
When a security breach threatens the dig (and Corrine), Michael will do anything to keep the cowgirl safe, even if it means hogtying her with her own lasso.
Can they make it out alive? That’s anyone’s guess. The only thing they know for sure is that the road to happily ever after is a lot more dangerous than they ever thought possible…