Calling parents of 14/15 yr old boys!! Advice wanted re: going out

[directoroflegacy]

DS is 15 in May - every school holidays we have the same 'argument' re: going out with his friends, in that he doesn't.
He says he texts them but they don't reply (am reading between the lines here!)
He does alot of extra curricular stuff - scouts, St Johns, volunteering, rugby but not socializing.
So is it-
a) he is so tired during term time he doesn't want to do anything?
b) speaking to friends is easy nowadays with FB, Skype, they don't NEED to physically meet up - this is his view and I agree up to a point
c) he is Billy no mates

So does yr ds go out?
I appreciate that this isn't the worst problem (if indeed it is one) we could have with a teen but any advice would be gratefully received!

If he's happy don't worry.

My 19yr old DD didn't have much of a social life till at least 6th form but at uni she's fine (always had lots of mates though).

DS (17) has only really started getting a social life and DD2 (14 nearly) never meets up with her mates.

Very normal. It was 6th form before ds started going out, and then it tends to be the girls that arrange things. He hs one friend who will get everyone together every now and then to go for a curry, or to meet in the park to play football, but if that mate doesn't organise it, then nothing happens.