Any suggestion why?
Your code makes no sense. In the first half of MyMethod() (up to line 16), you're setting the parameters for a QMessageBox dialog of some sort, then posting it with exec().

If you click something other than "No" (like "Yes" maybe), then from line 18 onwards, you set up the message box parameters *again*, exec() the message box *again*, and then recursively call the same MyMethod(), which then posts the message box, and so on..

So what you are probably seeing is the result of unwinding the stack after two passes through the same code, because you've gone into MyMethod() at least twice.

If your poor user clicked Yes every time, he'd never get out of the recursion. Click Yes, click OK, click Yes again, click OK again, click Yes again, click OK again, until finally he's going to kill the process, uninstall your app and ask for his money back.