When your children are already in their teens, sometimes you might feel that you have lost them. Daughters might not be daddy‘s little girls anymore. They make friends and they would tend to hang out and joke around. Maybe you get afraid of the way they socialize with others because you remember what things you were doing then. It is not easy, of course. You might be getting paranoid of the things they do outside your home and who they are with. It is not just their physical safety but you also think of what happens to them and the values that you have taught them.
Young people would sometimes get carried away by the things their peers say and do. They might feel that they need to do those things too and you sometimes do not want them to do those things. Especially in secret. (Unless they actually blog and put all the information there.) They want to explore their personalities and you probably do not want to be passive about it but at the same time you do not want to be too strict.
What you can do is to make sure that you and your sons/daughters are open to each other. Communication is very important especially in this stage. You are worry that your teen might run away or be too fixated on the computer and internet or a hobby. In any case, you have to talk with them, not talk to them.
Also, note that it is not that your teen sons/daughters do not love you when they do not talk much with you or show affection. Especially when they are around with their peers. It is more of them finding out who they are. Just be patient and things will follow through.