I would think it could be ejaculation fluid.
Cuz when we get turned on, a little stuff comes out of our penis. The only way for women to stain their underwear is if they crap or pee in it. That is usually unlikely too
I'm not completely sure of your explanation of the boys underwear. Was his penis inside the underwear? Or was his penis out through the opening? If a boy has his penis popped out thru the fly in his underwear, and his penis is in the area of, or in her vagina and he has an orgasm or he has the pre ejaculate fluid that comes in contact with her vagina. Yes, she could get pregnant. If he has his penis inside his underwear up against her vaginal area she might or might not get any sperm close enough to get her pregnant. Unless they have started making underwear for him out of latex (like in a condom!!) cotton has never been considered a good method of birth control.
No.
By wearing the right underwear....I will recommend natural pouch underwear.
no
It will not harm you, doctors say you should wear loose underwear to increase your sperm.
a penis and a ballsack with balls in it
Your pee made stains on your penis? Ask your doctor about pee stain removal.
No, because boys have small penis's
penis
Boys' underwear has space for the genitals. Girls' underwear does not.With boxers, the difference isn't so important, because there is plenty of room.Also, most mens underwear have flys so they can take their penis out easier when going to the bathroom
No, but wearing tight underwear decreases the amount of semen you produce compared to those who wear boxer shorts. Do not worry if you wear tight underwear - it will not make you infertile.