I am wondering if this is a common NT trait.
When you are in relationship you can never be fully commited.
You like the person and everything works fine. But you stay somewhat reserved no matter how good it gets. It has nothing to do with fear of commitment it is just that you can't achive emotional intensity.
So it can happen that you feel stupid since you can't return affection in that moment.
What can hurt the other person .
I am sure that this can happen to other groups as well. Since this is probably related with T.
EDIT: In post 19 there is the explanation about what this is all about