Like many others we also brought the gift of norovirus to our family. Eldest DS and I came down with it on 22/12... it was so bad we moved into the bathroom with pillows and duvets... and wow, the cool tiled floor was so amazing to rest your forehead against....we staggered out 2 days later on Christmas eve like mere sweaty shadows of ourselves and vowing never to speak of the moment he had actually shit on my head while I was vomiting down the toilet.... think "Bridesmaids, Wedding Shop scene"... anyways... we had survived and we were ready for Christmas!
We informed my parents that it was obviously just a 24 hr bug and we were over it so they arrived on Christmas day... and promptly caught it.
My mum and I are thankfully wonderfully close but I'm not sure she ever forgave me for the gift of Christmas shitting.
Another one which is more about me feeling ashamed of myself for being a bit bratty. My mum (single parent) had saved all year to buy my sister and I a computer.
This was back in the days when it came with a cassette deck and you had to spend eleventybillion hours typing code to get it to do something rather unimpressive... anyways we were both excited and overwhelmed.
Fortunately my mum's uncle and cousin had come to stay for Christmas and within moments of the computer being unwrapped the cousin (a grown arse man by the way, not a child), had commandeered the computer and spent the next three days completely monopolising it while my sister and I just sat on the sofa watching him... (and hating him).
No one could put the telly on either because he was concentrating.... so my mum was definitely regretting her choices when granny missed out on the Queens Speech.
Sis and I never really touched the computer after that. Cousin had demonstrated that it was an utterly boring gift....
Looking back, while I still think the cousin was a total nob, I feel ashamed that my mum had invested hugely in something she couldn't afford with a clear hope of inspiring us, she saw it as an educational opportunity for sure, and as a result of not getting first dibs on it we basically ignored it...
I mentioned it to her recently and she had thankfully forgotten us being ungrateful but remembered what an awful house guest the cousin was.... so maybe more him than us.