How thick should a erect penis be?

I'm 17, almost 18 and my penis is 3 inches when non-erect and 5 inches when erect, will my penis continue to grow?

what does it mean when a guy says a girl is thick because they say if you are not fat and you are not skinny then you are th...

With a 4 inch penis can you still have foreplay?

what is it when a guy gets erected?? like i know it makes his penis bigger but what is the prosses to do it and like how is i...

This guy I like has a really thick piece and its long too. My mouth is average and when i put his stuff in my mouth i can get...

What are some reasons why a boy's penis can't stay erected?

can you show the treatment to stop erections.

Do some men have hair half the way up on their penis shaft, and is this normal ?

How long does an erection stay and how to increase it thru diet and excercise

Umm this has been on my mind. How do you get a erection? Like how does it get hard?Do the muscles contract or something?