A bad guy or bully breaks someone's stuff, either trying to upset them, get revenge, get information, or for any other nefarious purpose. There's a beat, as we see the victim's reaction. They're usually looking either utterly deadpan, slightly confused, or oddly, a little smug. Then comes the punchline;
"That's not actually mine."
For added facepalm value, the broken thing actually belongs to the [...] [tvtropes.org]