It depends on when you started puberty. Most boys begin puberty at 12 or 13 years of age and for those boys most will finished the major body changes by the age of 18 or 19. Penis growth usually begins fairly early on in puberty and tends to tail of a little before the end so, generally speaking, most boys would not expect to see a great increase in the size of their penises between the ages of 16 and 17. However although most boys start puberty age 12 or 13 the range which is considered normal for puberty to start in is anything between 9 and 15 or so years of age. Obviously if you started puberty at age 14 or 15 you would not finish puberty until your early 20's and you might reasonably expect some significant penis growth between the ages of 16 and 17.
As for the normal size, data collected in a survey conducted by LifeStyles Condom Co. (one of the most accurate studies conducted to date) concluded that the average erect penis size for a fully developed adult male is approximately 5.877 inches in length and 4.972 inches in girth. The median length (where 50% fall above and 50% fall below) is approximately 5.65 inches.
Your penis could keep growing though it may be a slow growth. Sometimes the penis may get thicker, others it may lengthen but you are better off accepting the size it is. You are a young man and well it is said men grown up to the age of 21 even up to the age of 23 and this means you can grow from any part of your body including your penis. You are a lucky man there are many man that are not even 10cm. Be happy with the size.
At 15 most boys will not have finished puberty and you could expect that their penises would still have some growing to do before they reached adulthood.
Dont be silly.
I'm 15 and i have a 8 and 1/2 inch penis and the average penis for a 15 year old boy is 6.2 inches when erect and 4.1 inches around
No, you will be alone forever.
Not to sound rude but i highly doubt that u have an 18" penis
That is perfectly fine.
no youre a freak
heck no. and you don't have one.
no its perfectly normal. your penis should have started growing at age 14
If it is large enough to successfully urinate, stop worrying about. It's fine.
No it is not bad. Most are not straight.
no
Yes, if you have the macro penis gene or by penile enhancers.
your gay