Adrenaline Heat by Carolyn Reilly

Protecting her sister means destroying the only man she’s ever loved.

Birthed to fight and kill, Oliver Shaw is a genetically engineered superior soldier. Finding solace in the arms of his new wife, Luna, finally gives him a sense of peace. But when he discovers that Luna not only betrayed him but also the Committee team they both work for, Oliver’s world is shattered.
Saving her teenage sister from certain death means Luna Faris must deceive the man she loves. When she fails, the girl is at GovCorp’s mercy. And Oliver, who wants nothing to do with Luna anymore, is her only chance at getting her sister back alive.
Now, Luna must find a way to convince him to play a dangerous game dictated by the same corporation that created and abused him as a human killing machine. With the odds stacked against her, will she be able to save her sister—and her future with Oliver?