Everyone at work, at the coffee shop, at the library, at the synagogue seems to be talking about the Ugly Sweaties parties they're invited to. You've heard about them--those are the usually office-centric parties where you are required to wear the ugliest Christmas/holiday sweater you can find at Goodwill. Except now, it's such a popular phenomenon that you can buy these special horrible sweaties at Target and Urban Outfitters and Kohl's.
What an embarrassment, though, if you bought what you thought was the funniest, most unique sweatie at Walmart, only to realize that Jean from accounting is wearing the same one!
I've participated in these parties and I even suggested one at my last job, but I guess it's one of those snotty things--like, once everyone's doing it, it's no longer funny and cool. And then you start to see the variations of sweaties that allow men to talk about their favorite subject, the penis.
And women too, can use it as an opportunity to show off their stuff.
I prefer the more traditional ugly sweaties, such as the ones below circa 1952 (though again, this may be an ironic ad from UO).
You could go the cynical religious route as well.
Unless you are a person of color, you should not wear a black Santa sweater.
Adam, this last one is for you.