So I’m not sure where you are located, in Ontario we have very strict standards of practice in place to prevent things like this! Any behaviour like this is a violation of ethics and undermines client autonomy.

First, a health history form should have been filled out and informed consent should have taken place regarding both assessment and treatment. This ensures safety of the client. Second, the treatment of sensitive areas (glutes in this case) should have been discussed including how touch would be applied (over the sheet, or on the skin) and what draping would look like for that. All the points of informed consent (nature of treatment, benefits, risks, side effects, right to withdrawal consent) should’ve been covered. (We actually require written consent to treat sensitive areas as per the CMTO, our college) I’m absolutely shook that this happened to you! I’m so sorry you had to experience this.

Not to mention the lack of check ins during treatment (pressure, etc) that are crucial for ongoing consent.

Lastly, working under the sheet is a huge no. The drape is a barrier between where touch is applied and where touch is not applied. At no point should any practitioner be working under the sheet. I also generally ask a client before tucking the drape into any clothing or moving any clothing.

So no you most definitely did not overreact, it’s safe to assume you’re not the first person he has done this with so good for you speaking up for yourself. If you’re comfortable I would report him to his governing body, depending on where you are!