NoItIsn't

Let's say there is absolutely no reason whatsoever for you to say anything, but if you don't service your over-inflated sense of self worth or type 2 control freak personality disorder you're convinced your genitals will fall off and immediately burst into flames.

What do you say?

What if the conversation is between quantum capable physicists talking about quantum entanglement?

You can safely say, "NoItIsn't".

This statement will allow you to get in the way and be annoying at the same time.

Win-win.

Other variations are:

"I'm sure it's not like that"

"NoIt'sNot"

"That's what you think" (say this in the smarmiest voice you can muster)