What does Aunt Harriet mean?

Aunt Harriet meaning in Urban Dictionary

you (usually a relative) whom seems to either be attracted to (or even more likely to like or take the medial side of) the folks who're many harmful for your requirements. Coined after Aunt Harriet from old (Adam West) Batman series just who, if she liked a fad, it is possible to bet it was a front when it comes to villains.