18year old son

My son has Aspergers. He is a good student, and has some great friends (he has gone to school with the same kids since kindergarten)
He does not go out with his friend much, but they don't seem to mind. They text and call him and play online games with him. For the most part he always has good friends around him. I am VERY thankful. J has had a few problems that are difficult to deal with. He has anger outbursts (usually very short and he will usually say he is sorry
last year he started vocational school offered through his high school. He loved it. Made New friends. Made a great connection with a girl A.
They were friends all last year, tested all the time, still the same at the beginning of this year. But just this week I got a call from his teacher. She said A wants J to stop contacting her. She asked him to but he won't. She wants to stop being his friend.  There was another girl who was in their group of friends who said the same, she don't want to be his friend. They say it's to difficult. He got very upset and threatened suicide.
Any way when I questioned him. He said the girls said they were his friend, but they were mean to him. He said he would never hurt himself, he just s as I'd that to hurt them like they hurt him.
I think most kids have friends trouble. But I hate that he never told us what was going on. And when we did talk about it, it was like pulling teeth.
He is so upset that they don't want to b friends anymore. He is he art broken. I hate it.
It's difficult for him to understand boundaries.
His teacher said he Crossed boundaries,  He does not 100% understand.
But I think the girls did too.
I just feel bad.
There was never a issue like this in his home school.
He loves the graphic class he takes, he does great in the class.
How do I teach him about boundries

[copernicus581]

It is so hard to teach someone with AS about boundaries because they won't see them. They're invisible and they will never see them. Imagine if someone told you there was an invisible string in your hallway and every time you walked into it you tripped and hit the floor. Now, how many times out of 10 would you remember that invisible string? Probably 2 or 3 times if you had an active never-stop-thinking mind like an Aspie does. For me it is extremely hard to remember boundaries and i imagine its just as hard for your son. One way, is to let him know how other people feel when he steps over a boundary and how they may react. Draw him out a diagram, or a T chart or a table chart of some sort. It is easier for someone with Aspergers to draw information in that form.