>>1930325"Christmas cake" describes a woman above the age of 20, but not in a serious relationship or not yet married. It equates them to the namesake pastry that doesn't manage to get sold during the holidays and just sits on the shelves at a discount, although they're perfectly fine goods.
Leave it to nips and weebs to feel the need to categorize women who are basically in their prime, mentally and physically.
But thank god for this thread.