Enough
He doesn't know everything about her but that's all right. What he does know is enough. She's strong and reliable and he'd like to have no other person watching his back.
She knows as much about him as he's willing to tell and more. She's good at reading people and he's an open book, at least to someone like her. What she knows, she likes. What she sees meets her approval.
He knows she's dangerous, an operative from a country at odds with the U.S. He'd tease her that there is precedent for operatives switching sides and she'd give him a blank look, not getting the joke. That's all right, her humor is as deadly a thing as she is herself.
She doesn't always appreciate his jokes. She's sure not all of them are funny – even to someone who speaks native American (not English; American is something else entirely). It's all right. They have their own shared jokes.
He understands, no matter what happens, she will do her damnedest to get him home safe.
She understands he will protect her with his life – but that their lives were secondary to the lives of innocents.
On some nights, some quiet, rare nights, they curl up together, skin to skin, breath to breath, sharing each other's warmth. This, he thinks, could be love. She thinks it's something else. They both agree there's no one else they'd rather share with.
It's enough.