The only problem was the nature of her relationship with that man.

"What was the nature of your relationship with the victim?"

Something that told him about the very nature of our relationship with the sun.

If they don't love each other, what is the nature of their relationship?

I remember talking about the nature of our relationship, how she got in.

"What was the nature of your relationship with her there?"

"I should like to know the nature of your relationship."

The nature of their relationship to birds is under discussion.

Rita is kept in the dark about the true nature of their relationship.

That was not the nature of their relationship any more.