Sentence transformation with "say"

In an exercise, a sentence is given:

I think it would be best if you didn’t mention John’s behaviour to his mother.

The task is to write a second sentence that has exactly the same meaning, using between 2 and 8 words inserted into a given template:

I don’t think you … John’s behaviour to his mother.

An additional requirement is that the word say in exactly this form must be included.

Can someone please help?