The phrase "how to ruin Christmas" is mostly associated with a South African comedy TV series titled "How to Ruin Christmas" that centers around family chaos during Christmas time, including events like a wedding and a baby shower. The series humorously depicts how the protagonist Tumi often causes disruptions during family Christmas gatherings, such as nearly ruining her sister's wedding or causing tension during holiday events. It focuses on familial drama, mistakes, and attempts to make things right during the festive season rather than literal advice on ruining Christmas.
If the inquiry is about actual ways people might spoil Christmas, like common scenarios or behaviors people associate with ruining Christmas spirit, this specific series-based content does not provide direct advice or tips on that topic. Would a description of typical behaviors or events that might "ruin" Christmas for people be useful instead?

