A key university teacher contacted me online for more than three years ..... and even laughed at me face to face for several years.

This is not necessarily sarcasm, because you are sensitive to this question. The so-called once bitten, twice shy, normal teasing may also be mistaken for teasing.

But this article has a premise, that is, you two have a certain connection, or not a relatively strange relationship. Judging from your vote for him for three years, you should be familiar with it. He probably doesn't know you care about this, so he's not kidding. The nicest thing I've ever heard is to describe that two people have a good relationship, so good that they insult each other ... this situation is very common in families and men's circles, but rare in women. Even if you use "she", it's hard to say.

Of course, this is just an explanation. Judging from your description, it is a reasonable explanation, but it doesn't mean it is correct. Depends on what you think.

Personally, what she said, "You are a strange man, I admire you very much …" is nothing like thinking. ....