i didn't do it
A fake confession with a disclaimer that makes it sound like you're trying to trick people into thinking you're crazy.
'I did not actually do the bad thing,' he said, then added, 'this was just for laughs.'
'I did not steal the pie,' she said, but then she ate the whole thing.
'I did not break the law,' he said, even though he was wearing a disguise and had a warrant.