You hope your teens make the right choices, but sometimes even the right choices feel wrong.  He is choosing to be away with friends and not at home much.  I believe this is healthy, but I can help but want something different.
That's what my own mother says.  In fact, she said my dad had a harder time than she did when I called and said, "Hey, I'm staying the night at so and so's, be back tomorrow."  I guess I will survive!  Hopefully he will choose to spend time here as he hits his 20s!