I have always assumed he is, but I am reading more about it and would like to be sure that this is not just normal teenage stuff.
I am listing a general overview of his behaviours here, he is 14 years old:
Very tactile and affectionate with myself, his sister and the dog
Insecure away from home or from me
Hates visiting his (probably also on the spectrum) father who is v judgemental
Obsessive during play and only has one interest at a time, which can last for years
Is either very tired or hyperactive; no middle ground unless he is concentrating on his current hobby
Doesn't have friends his own age but can play with boys a few years younger although these friendships don't last long
Has a few female friends his age from what I can tell - the girls at school are nice to him - but doesn't initiate contact with any of his peers
Forgets simple instructions all the time (eg now go to the shop to buy bread) but can do complicated electronics
Cries very easily, used to be a couple of times a day but less often now
Throws anger tantrums with moaning and wailing for ages about tiny details; then forgets what it was about but continues the tantrum
Blames those around him for perceived failings of his own
Can talk to adults easily about what they are doing (when he travels with me to work) and slightly attaches himself to them sometimes; they think he is lovely.