If you have a cite for that conviction I would be much obliged to see it. Presumably the Scottish Daily Mail had a field day with it.
The urban myth still gets recounted in Edinburgh medical student circles about the undergraduate who walked around with an actual penis (from a corpse) protruding from his fly, and when reprimanded about this, took out a scalpel and cut it off.
I got this from the “Straight Dope Page O’ One Liners” a very long time ago and I forgot who posted it, but it seems appriate here:
I call it “No-Pants Wonderday,” but it turns out the police just call it “Thursday.” Go figure.
This is the real answer, surely? 
Google skirt and Bralet. It’s a pretty common fashion these days.
y’know, 12 and a half years is a long time to hang out in your undies unless you are living, like, around here by the beach.
I believe that the Law in NYC is that in public you *have *to cover your delicates even if body-painted (as observed in Times Square for the past two years).
I believe in most states you can actually walk around your front yard completely naked and the police can’t do anything about it since it’s your own private property unless you’re touching yourself sexually and thus violating some sort of indecency law.
A lot of women go out running in nothing but a sports bra and a pair of shorts (and running shoes) and no one thinks it’s odd. I have never seen a man go running in nothing but a thong (and running shoes) but I suppose it’s ok if he enjoys sunburn and bug bites. Most male runners I see usually wear some type of shirt. I don’t really understand why we have “decency” laws that require people to wear clothing. People can be quite indecent while fully clothed and fully decent while naked.
If you tried to go shopping or into a restaurant wearing minimal sporting attire they would probably chuck you out on the “no shoes no shirt no service” principle.
It doesn’t make sense to say just underwear=bad, trousers=good in some statute book somewhere, because I could easily find a pair of spandex pants that prominently show off my erect junk. And meanwhile, like you say, some underwear just looks like shorts, and what about a person on a street near to the beach wearing only trunks?
There has to be common sense on this; the police have to make a judgement call. If the police see you and think you’re obscenely dressed, especially if members of the public have complained, then they can detain you briefly and issue a fine or whatever. Or maybe just let you go with a warning after recording the incident and giving you something to put on.
This is based on a loose understanding of how it works in the UK, but I suspect as a practical matter it has to be handled something like this in most secular countries.
All the sports bras in which I’ve seen females out running in public, seem to be styled to be seen in public. They cover more than most regular bras as far as I know, and certainly more than most bikini tops, and typically aren’t sheer or lacy or otherwise looking like dainty underthings.
Indecent exposure laws very a lot from state to state and sometimes city to city. There are cities where walking around fully nude is OK (I believe San Francisco is like this), and other places where a lot of bathing suits won’t pass muster. Nipple coverage often depends on sex, and gets complicated because of breast feeding and the fact that it’s clearly a case of sex discrimination. The part of NY’s law that forbade women going topless was ruled unconstitutional on equal protection grounds. A number of places have a law against clothing that exposes the shape of an erection, so a man running around in contour-hugging fabric may have trouble if he gets arouse. For the most part what you need to do is cover the genitals, anus, and female nipples to be OK legally, though legality doesn’t stop local cops from hassling you. Boxer shorts and an undershirt is legal most places (presuming your junk stays covered), I know it would not hit any laws where I live, and I’m not aware of anywhere that has a law that distinguishes between ‘underwear’ and ‘outerwear’.
As far as walking though a mall, the mall is private property and can kick you out for any reason that isn’t “because you’re in a protected class”, it’s just like ‘no shirt, no shoes, no service’ at a restaurant. If you refuse to leave then you’re trespassing, and the cops will cite you for that and probably won’t bother with an ‘indecent exposure’ charge even if it might technically violate a local statute, because trespassing law is really clear on this kind of thing and is what the mall will want them to cite you for (because you get in more trouble if you come back after getting cited).
Isn’t that basically what the yoga pants crowd does?
I mean some of them are so tight you can spot the camel toe no problemo.
I looked but failed.
Don’t forget that there are different legal systems in Scotland, Northern Ireland, and England and Wales. But in any of these jurisdictions it would be a matter for the courts to decide in the light of fairly generally-worded laws on indecent display or some similar wording (the law doesn’t prescribe everything about its potential applications).
Unless, of course, someone gets an Anti-Social Behaviour Order injunction against a specific person, in which case, there can be bizarrely draconian results:
http://www.telegraph.co.uk/news/general-election-2015/politics-blog/11664860/Naked-rambler-why-have-we-spent-300000-imprisoning-this-harmless-eccentric.html
Sure, but what I’m also saying is that in most cases it will just be a judgement call by police and is unlikely to make it into court.
So while the answer to the OP is that he may not run afoul of any specific laws by walking around in tight briefs, that doesn’t mean he won’t be stopped by the police.
I suspect that this kind of thing is relatively common – think of all the young people trying to push against social norms, and all the elderly people failing to dress adequately because of, for example, dementia.
It’s the kind of thing police need basic powers to deal with, but also, as it’s so trivial, it’s unlikely they’ll try to make a conviction.
Apparently, it’s only an offence in the UK if your intent is for someone to see your genitals and cause alarm or distress. If you are not intending to cause alarm or distress, you can walk around naked all day.
In Cambridge, there’s a man who rides his bike naked, he is not out to cause alarm or distress, so he can ride around as much as he likes. Of course, not all towns are as tolerant as Cambridge
One of the tenets of law is that intent may be presumed from the obvious results which flow from your actions. Although you may wish that people were not alarmed or distressed by your public nudity, you almost certainly know that by appearing in public nude that people will be alarmed and distressed.
Therefore, if you choose to go nude into public knowing that by doing so people will be alarmed and distressed, your intentional choice to walk around nude means that you intended to alarm and distress people.
Boulder. Actually many but not all jurisdictions. And cops are not above hassling people for doing things that are legal.
I’ve seen guys walking around buck naked in S.F.
I remarked to my wife “Well, that’s something you don’t see every day (and thanks for that)!”
In Times Square, the Naked Cowboy performs in briefs, cowboy boots and a hat, and a guitar hanging at waist-height.
No, it doesn’t depend on a city’s cultural mores or on city law. The people commenting on this don’t know what they are talking about. It’s legal to wear underwear in public anywhere. This is not a complex issue.