I feel your dad was in the wrong the way he handled it. The problem is that he is your father and I know you don't want to cause a huge issue about it. As it has been pointed out a collar like what you described is not that an uncommon thing to be worn, bdsm or not. With your outfit hardly out of place.

Did your dad not like non conservitive clothing ever? I bet he had some idea what else it may mean as well. In the interest of family peace having a small privite chat with Dad about personal space and respect may be called for. I would not wear that again after depending on his reaction to the conversation. Sigh parents. My mom learned a long time ago not to ask me if she did not want to know the answer. The response she got once from her telling me she heard me saying ow in the bedroom on night and seeing a bruise on my thigh was more than she could get her head around..she just does not ask hahaha...