Manipulate by Pam Godwin

Tula Gomez is in the most ruthless prison in Latin America.
She only drove to Mexico to help her sister. She did nothing wrong.
But her quiet life changed in an instant.
To survive the violent, cartel-controlled prison where men blend with women, she pledges her loyalty to the notorious leader in exchange for the one thing she needs most.
Protection.

When she agrees to seduce the suspicious new inmates, Martin Lockwood and Ricky Saldivar, she doesn’t expect to enjoy it. Sure, they’re gorgeous, irresistibly alpha, and insanely talented with their hands and mouths. But they’re the enemy. She can’t fall for them.
Torn between her cartel loyalties and two men who want her as deeply as they want each other, she questions who is manipulating whom. Her search for answers leads to a passionate ménage, a soul-crushing secret, and an impossible choice.