What is the fundamental difference between underpants for men and women?

Men's underwear have that flap in front, so they can pee standing up without pulling their trousers all the way down.

Nope

It's not that simple... The answer is scientific.

The only thing that comes to mind is that men's underwear has the crotch flap to enable peeing without pulling down underwear and jeans or pants.

What about boxers being better than briefs when a couple is trying to have a baby? Wearing boxers instead of briefs is supposed to improve the man's sperm count.

   The last answer is in the right direction, but it's only touching the surface

uh...*shrugs*

the resevoir tip!

Grrrrrrrrrrrr!

   And the full answer will have to do with women equally, not only with men

Tease!

Men's underwear has a Y front. This is there purely for decorative purposes. I don't know anyone who actually puts his penis through it when he pees. They aren't really that functional.

The main difference is to do with the main difference between men and women. No I'm not talking about the ability to multitask or navigate.
I'm talking genetalia.
Olde worde mens underpants (Y-fronts) had a hole/gap to slip the *cough* y'know through when going for a pee. Not that I ever used that. Same for boxer shorts. The brief style has extra material in the front to make room for the er..*cough* y'know.
Women don't need all that stuff.

Women's underpants are pretty. Men's look dumb except for the long surfer jams, which I have a soft spot for.

I assume you're looking for the "style" vs "comfort" answer.

Notice how only women believe the Y is functional.

There's a flap in the front of men's underwear?

   Nope, I'm looking for a scientific answer that has to do with biological reasons (see the hint in the explanation) why male and female bodies are constructed differently

   Kate's answer was the closest to the truth so far But it was only close - not the truth itself.

   Can you do it with an additional hint, that I told to Zang?

I must be brain-dead because reading what you posted to Zang didn't seem to get me any closer to the answer.

Has it anything to do with the crotch design of womens' underwear which is quite different from mens' or because womens' openings are lined up between their legs and their underwear correspond with that? Am I getting any closer or am I moving farther away from the answer?

hhhhmmmm, the extra entry way?

   Farther. The answer has nothing to do with design. Of those reasons I told to Zang, the main one is temperature

Guys pants have more room in front and less in the back? I really have no idea - not one of my areas of study!

Um, maybe guys' underwear ensures the testes are kept away from the body so they stay at the right temperature.

I have never studied the way men's bits fit inside their pants!!!

Men need their testes to stay away from their body so that they are cooler and end up having a higher sperm count.
Women need cotton underwear so that they don't get infections as easily.

Okay, here goes. When a man wears briefs instead of boxers, it increases the temperature in the groin area (because of the snugger fit) and lowers his sperm count. Boxers on the other hand allow the temperature of the groin area to stay at a more comfortable level which keeps Mr. Sperm happy. Is THAT the correct answer?

   Ok I'm looking for an answer that would explicitly link it to differences in male and female anatomy - and would cover men and women equally

   The last part of the answer needs to be fixed - see the reply to Biggles

   The same comment as to Biggles *points up*

*sigh* I give up!

Well, I don't think I have any more ideas! lol

   All of the last answers (yours, Kate's, Oscar's), are basically correct, but I want you to say why female and male anatomy is different in first place - the anatomic reasons. Everything is already there, and you don't need NEW ideas, you just need to expand the answer a bit and tell what you would do if you were Nature - how would you construct male and female bodies?

   All of the last answers (yours, Biggles's, Oscar's), are basically correct, but I want you to say why female and male anatomy is different in first place - the anatomic reasons. Everything is already there, and you don't need NEW ideas, you just need to expand the answer a bit and tell what you would do if you were Nature - how would you construct male and female bodies?

   And look at what I posted to Kate and Biggles

Light bulb and socket so to speak

As in, women's reproductive organs need to be at body temperature in order to work at their optimum. Whereas men's need to be below body temperature in order to function optimally?

Not sure what the reason for the different optimum temperature is though. Presumably different enzymes at work.

   And for that reason, if you were Nature, you would construct male and female bodies how?

   And after you answer that question, can you give the full answer to the survey question as well?

I would put women's reproductive organs inside their bodies, and men's on the outside. So women do not need room in their underpants for external genitalia, whereas men do.

   Eep! The first phrase is absolutely correct, but the second is not the main consequence

Well, I don't know!

Men's underwear have extra space up front in case they get an erection.

   Unfortunately, that never helps... lol

   Anyway, here's the full answer... Female and male sexual glands need different temperature: female glands need the temperature of body, and that's why they are deep inside, and male glands need a lower temperature, and that's why they are outside. (Higher temperature not only reduces the man's chances to have children, but even increases the probability of developing cancer. And lower temperature not only reduces the woman's chances to have children, but also increases the probability of getting infections - the same mechanism that causes you to catch cold.) And that's why men's underwear has to be loose, and women's underwear has to be warm - exactly the opposite.

   Kate gets a cookie for getting on the right track first

   Oscar gets a cookie for mentioning infections

Oatmeal chocolate chip please, made with butter, not margarine.

   And Biggles gets a cookie with fruit jelly for introducing the notion of optimal temperatures and finally telling why female and male bodies are so different - it wasn't evident, male glands could be inside as well, but they aren't

   LOL I didn't even finish handing out cookies, and you already replied

You SAID I was first! (running out of the room crying) Meanie!

OIC! Well, it was just a guess.

   Oh Kate... Now I'm sure that Oscar will get hurt too, just because I gave each of you one cookie, and not the whole pack *munches on one more cookie, then becomes aware of being watched and hides it hastily*
   

   

DOUBLE MEANIE!

But just out of curiosity. Do any men use the flap in Y-fronts to actually pee out of?

   Make a survey on that Myself I doubt it.

Mens' have a hole so you can pull out your penis. To me main difference is that mens' underwear is boring as hell. That's why I only wear women's.

Oooh, oooh, ooooh

   

Well I'm not making this survey. I'll just get a lot of 'needs work' saying what about us women? Can we not vote. er...no!

The flap in the front of men's underwear.