"Is it healthier to wear boxers or tightie whities?"
Kris, 19, Coral Springs, FL
It's all about what's most comfortable for you. Tightie whities offer more support than boxers do, but there's no medical evidence that one type of underwear is better or worse for your body.
"One of my testicles is bigger than the other. Is that normal?"
Josh, 17, Virginia Beach, VA
No one's body is completely symmetrical, and that goes for parts of the body that come in pairs, like testicles and girls' breasts (even your eyes aren't exactly the same if you look closely!). It's normal for one testicle to be a bit bigger or to hang slightly lower than the other. The only cause for concern is if you notice one suddenly growing faster or starting to feel firmer than the other. If that's the case, get it checked out by your doctor.
"What is the normal size of a penis?"
Matt*, 17, Bellingham, WA
How did we know someone would ask this? Guys obsess about the size of their penis the same way girls do about their breast size! How large or small a guy's penis is varies by his genes. But we know you want a "definitive" answer, so the average size of an erect penis is four to six inches long.
"Why do guys wake up with an erection?"
Joseph, 18, San Leandro, CA
During the day, your mind inhibits most of the erections your body naturally wants to have — mostly to prevent embarrassing moments. But during deep sleep, your brain lets go of all your daytime inhibitions and your reflexes take over (an erection, which is just a sudden flow of blood to the penis, is basically a reflex). Erections come and go naturally all day and night — and sometimes you wake up with one.
"I've had a lot of wet dreams lately. Why is that?"
Thaddeus, 20, Hannibal, MO
You must be pretty into someone right now! Unlike nighttime erections, wet dreams (or nocturnal emissions) happen when you're having sexual dreams. And they can happen more often when sexual thoughts are front and center in your mind. Wet dreams are more common around your teens and early 20s because that's when your hormones are working overtime.
"Are you more likely to get an STI if you're not circumcised?"
Kejal, 22, Nutley, NJ
This is a controversial subject, but most doctors say guys who are not circumcised (meaning the foreskin that covers the head of the penis has not been surgically removed) are no more likely to get STIs than those who are circumcised. Either way, every guy needs to wear a condom to protect himself. P.S. Are you really from Nutley?!
"Can a guy get a girl pregnant if they're fooling around with their underwear on?"
Kyle, 17, McLeansville, NC
Sperm is smaller than the holes between the fibers in your underwear, so your semen can pass through and come in contact with her vagina, and she could get pregnant. The risk is small, but it's not zero, so don't risk it.