Teen son so distant

[Jcx1972]

Oldest DS is 15, nearly 16. Family of 5 and I would always have described us as close. DH and I have always tried to instill the importance of family and we've given our children happy and settled childhoods.
Over the last year our oldest has become so distant. He never volunteers anything about his day, if we ask he just mumbles a reply. We don't really know who most of his friends are since he started secondary. He barely speaks to his younger DB. This is something DH and I have raised with oldest a few times as we don't feel this is acceptable but nothing changes.
Overall oldest is a good lad. He never grumbles about going to school, mostly does his homework, rarely in trouble, grades OK. I suppose I'm just feeling sad that he's become so withdrawn from us all and am looking for reassurance that this is a normal stage and I'm being unreasonable to be worried?

That is quite normal for many boys of his age, some start younger than him. It doesn't last, don't worry.

Teens can be very hurtful by going into the 'withdrawing phase'. My DD stayed in it for about 6 years then came back from Uni like a different child. DS, however didn't go through this phase much at all - but then was distant in other ways (as in spent ALL his spare time on his Xbox). I have a wonderful relationship with both of them now they're living independently. I just chose not to make too much of a fuss about it-you simply can't force people to be sociable if they don't want to be.

As a mother of a now 22 year old son, this is completely normal. 2/3 years and he’ll come out if it.

This sounds normal OP, my eldest was just the same. It lasts for a year or two but then they come back to you.