The melody comes from 'Baby, It's Cold Outside', the 1944 duet by Frank Loesser that became a Christmas-season standard through countless covers. The six-second clip follows the Vine format that was popular in the mid-2010s: a tiny, instantly recognisable audio hook cut for looping. On TikTok the snippet is most often attached to winter weather clips, sarcastic cancellations and festive memes, which is why it keeps resurfacing every December even though Vine itself shut down in 2017.