Simply put, it is not weird at all for Mom’s to buy boxers for their boys, no matter what the age I think. Tighty whities and boxer briefs might be a bit strange, but even that I think I would tolerate. Jockstraps would be absolutely out of the question past the age of 16 (or once a kid gets a license and can take care of those types things on his own). While I buy some of my own boxers, typically when I go back to Mass for a visit, there is a fresh 3-pack of generic boxers waiting for me in my room, washed once, ironed and pressed, just as any good woman should do. Just kidding, there is a 3 pack, but they are still in the packaging, and Mom usually leaves the receipt telling her how much I owe here (insert generic Hebrew joke here).
So no, you have no reason to cringe when your brothers break out a fresh pair of boxers from their stockings in 356 days or so (holy shit, time goes by). Feel free to cringe, however, if you open up your stocking and find a lace thong from your Mom, that would be beyond creepy. Even big white panties (granny panties, or fart catchers) would be downright disturbing.
You know what else is disturbing? Going to a lovely family’s house for Christmas, feeling welcomed into their home, then watching them all open up the same pair of green and red J crew boxers, and putting them on for a family photo. Three generations of one family, ranging from about 3-65 all wearing the same pair of underwear. That is effing creepy. But wait, there is more…hearing an Uncle claim that there is no way he could “fit into underwear that small,” with a sly look on his face was even creepier.
But something tells me, Nifer, you are already quite aware of such a story. So if I were you, I’d stop worrying about a random pair of boxers, there are much bigger fish to fry.