No disasters, but my Stepmum going a bit crazy a few years back is the reason I no longer see family on Christmas Day
There was nothing clear that needed to be done, we'd asked about half an hour previously if there was anything we could do to help, and were told everything was fine. As such, we sat down to watch TV. After a bit, my Stepmum walks in, stares at us, and starts screaming at us, saying we're being 'Ungrateful' and 'Unhelpful', despite the fact we'd asked if anything wanted doing not long beforehand.

If she'd walked in and actually said what she wanted, no problem. Instead, she decided screaming at us was a better idea. Mental.

Alt: Nope.
( Agnostic Antichrist Baltimora, Fri 21 Dec 2012, 14:22, Reply)