Most of the parents have the same questions after they kids grown and they stop being boys and become teen or men all they ask and now what!!!
Why our kids stop to ride bikes, play games as super hero or stop to watch those Tv series for kid/teen?
Well here you can find some answers
first- They don’t stop to ride bike just use the bike to go to a friend house to watch some videos de sex on a DVD, Blue ray or freeporn videos in the PC or even in the PSP2 that used to be one of their favorite activity after the school.
second- Have you think that their needed change? of course now they keep pretending to be a superhero but not in the way that used to be, Now they sign up for some dateing site so they can be a superhero for their friends.
third- Now they watch those tv series online but not for what you thinks 
now they look online for some of their favorite start naked or in a sexual act.
So I recommend you that observe your kids that become men and women and for sure you will notice it.
And instead to punish them I recommend you to become their best friends and you’ll realize that we did the same at their age 