He had tried, for weeks, to keep things the same between them.

Still, she kept her body between him and his brother.

On the other hand, perhaps this was a matter best kept between the two of them for now.

The distance he had always kept between them was gone.

She closed it behind her, to keep this just between the two of them.

I thought we agreed to keep all this between us.

He drew back enough so we could see each other, but kept my face between his hands.

Something, perhaps, that she felt ought to be kept private between you and her.

Did he notice that she kept herself between him and Will?

If you're upset with your significant other keep it between the two of you.