4/M has bizarre behavior when meeting or talking to new adults

Just introduced my son to my new boss. He got down on the ground and started making roaring "dragon" noises and wouldn't stop. Like I carried him out of the office still making those noises and squirming in my arms.A few weeks ago he met an old friend of mine we ran into at the mall. He was in a stroller and unhooked himself and started spinning in his seat. He wouldn't stop making this high pitched noise. I eventually took him out of the stroller because he would not stop. He started spinning while laying on the ground and then in my arms and eventually we had to walk away.I want to include him in the conversation. It's not like we ever just ignore him when we meet people. But this has been going on for years honestly. Any new adult becomes a strange experience.I'm posting here because when I was walking out of the office today, I could see the receptionist say to my boss, "I think he was autistic." My boss shook her head yes.It's literally the only weird thing about him. He's really, really bright for his age and impresses people once he actually talks to them. We have normal tantrums, normal play experiences. He was in preschool last year and a year at daycare before that. Always good remarks about him and never a question about his behavior.It's to the point now where I cringe at the idea of introducing him to anyone. He and I talked before meeting my boss about what we would be doing, what she looked like, and what she might want to ask him about. Still an odd reaction from him and what's the strangest thing isn't that he's shy but it literally doesn't break until we're far removed from the situation.Advice? via /r/Parenting http://ift.tt/2sVaDIv