The penis usually continues to grow until a boy is about 17 but everyone is different. Nothing can change penis size-hormones decide penis size. Penis size does not matter for sex. Any adult -18yrs- can enjoy sex with their partner-what matters is how you and your partner understand and care about each other's sexual needs. Sex starts in the mind and depends how prepared you are with your partner and how you feel about each other.

Attribution: Straight Talk Foundation & Marie Stopes