ok, I will date myself ... startiing in grade 7 (canada) we had to change and shower for phys-ed. at that time the changeroom was divided into two groups ... those who wore skintight bikini briefs, and those who wore 'tighty-whities' which were usually 'loosest whities' because these were the underwear your Mom bought for you, and she wanted it to last as long as possible as you grew.
throughout my middle, and high school years, and even into university, boxer shorts or any desciption were considered the kind of underwear only an old fart (your day, your uncles, you grandfather) would wear.
Similarly, at any pool, beach, or hot tub, EVERYONE wore speedos. Male and female. young and old. being teenagers, we wore the tightest, tiniest speedos we could get away with, and if that meant trimming your pubes, you trimmed your pubes. the little kids paid no attention to the fit, whiile the adults tended to go for a fuller, looser, more modest cut. great advantage was the suits dried in fifteen seconds, extremely comfortable to wear.
then came a change in attitudes, and board shorts replaced speedos, and boxers replaced briefs. Now we come full circle, and briefs are becoming fashionable again.
Wonder how long this will last ... maybe like my observation this past summer during a trip to europe ... I have never seen so many fourteen-year-old-and-up guys who tweeze their eyebrows into perfect arches, shave their bodyhair, and wear those huge oversized versace sunglasses.
There is far more acceptance / acknowledgement that we are all human, and all have imperfect bodies in europe. here in north america, no guys take off their shirts for fear of exposing the fact they don't have chiseled six or eightpacks.