My wife has told me many times that she is afraid of me, and for many years I was puzzled by that expression, until it dawned on me that what she really meant, was that she feels vulnerable with me. English is not her first language, so while she is fluent in it, sometimes when there is a figure of speech, it comes out different in one language than it does in another. For instance, you wouldn't tell someone that they are being silly in her language, because the only word they have for that, is a word that means "stupid". Any way, "vulnerable" is a much better choice of words to use to express how she feels, for obvious reasons.