My assumption is (with some confidence, based on your description) that they were referring to something you said (or the way you said it) when you were “just blabbing on and on”, and that if you could get the context and the way they meant it, you would get that it was normal and not anything you need to be concerned about.
I think you just didn’t follow what the psychiatrist meant because, as you wrote, you “cannot read between the lines due to Aspergers”.
Psychiatrists listen to us from an outside perspective, which will often see irony, insights, or otherwise remark at what we say.
So I would suggest that next time you see them, you say something like, “I am curious to understand what you meant last time when I was blabbing on and on, and you said I was cute. I don’t know what prompted that or how to interpret it.”
This is clearly part of your experience of life too, good to share and relevant, and they may have some valuable ideas for you about that sort of thing in other situations.