He said he was going to help, but he was criticizing me behind my back
I found out that they were planning the surprise party behind my back
She felt betrayed when she learned her friends had been gossiping about her behind her back
You shouldn't do things like that behind someone's back; it's dishonest
He's been talking about quitting his job behind his boss's back
They decided to change the plan behind the committee's back
She didn't want to upset him, so she made the arrangements behind his back
It's not fair to make decisions about her future behind her back
He's been applying for other jobs behind his current employer's back
I overheard them plotting the prank behind my back
I heard you were talking about me behind my back.
That is not true, I would never do that.
I hope you are telling the truth.
He gossiped about her behind her back
He spoke ill of her when she wasn't there
He said mean things about her secretly