I find teasing very hurtful; this is a consequence of being unable to read people. I have to take everything I am told at face value, take it literally, because I am unable to determine intent based on anything other than the words spoken. I have to rely on people's honesty.
This means that whenever anybody says something about me I have to assume that it is their honest opinion of me. Because teasing involves negative comments - criticism or accusations - that paint me in a bad light, that suggest the speaker thinks ill of me, I experience feelings of betrayal that cause me great pain. My trust in that person is compromised.
An example: I have a close friend, somebody I used to work with, who is like a sister to me. Yet there are people I see socially who persist in teasing me by suggesting that there is a sexual attraction or relationship between us. As a married man I have an unshakeable loyalty to my wife - strong loyalty like this is not uncommon in Aspies - not to mention the implied insult to my friend. Knowing that behavior like that would be unthinkable to me - such impropriety - I am forced to conclude that these people are being deliberately malicious.
I fail to see their motivation, unless it is to cause me hurt. Yet when I challenge them they just say that they are "only teasing" and lay blame on me for not humoring them, for not joining in their childish games. They appear to assume that I can distinguish between this teasing and serious talk. Am I supposed to feel flattered that I can pass to this extent? Would they "tease" somebody in a wheelchair about their more obvious disability? I believe that less visible psychological conditions like autism, because they're not obvious like many physical conditions (I prefer not to refer to disabilities - we may be defined by society at large in terms of our impairments but I would rather focus on our abilities than dwell on those things that are difficult or impossible to achieve through accident or the roll of the genetic dice), are considered less real, less valid, as if these people believe that we could choose to think and act in a way they consider "normal".
Small-mindedness; unthinking, petty, vindictive cruelty. And for no better reason than their own amusement. I may be no saint myself but at least I would not intentionally cause someone pain. I would feel remorse and apologise if I was brought to understand that I had unwittingly done so. I would not try to pass it off as "only teasing": I would feel as hurt because I had hurt them.
Teasing. It is in the same vein as bullying in my book. And I have no truck with either.