Sometimes we say one thing when we want to say another.

Maybe you need to reject someone but you want to let them down easy.

It goes something like this:

Oh thank you Beth. That's such a kind invitation!
(hand near mouth)
You really think I don't know you only invited me because Susie wouldn't talk to you if you didn't?
But I'm so sorry. I have plans for that night.
(hand near mouth)
Like I'd be caught dead at your party if you were arranging my own funeral!
I really appreciate you asking me. Please keep me in mind for the next one.
(hand near mouth)
So I can invent a new excuse to be as far away from you as possible!

In this narrative, there's a big difference between the kind words Beth is hearing and the big objections going on in your head.

The people in your audience have all been in a situation where they had to force themselves to be polite when they wanted to be obnoxious. In this case, you actually do get to complain out loud. Beth will be none the wiser, but your audience will savor every word.

Note the eye and hand that cue the audience when you're speaking with Beth or sharing with them.