I can provide some general information about the typical practices in therapy related to self-harm and confidentiality.
In most cases, therapists are bound by strict ethical guidelines and legal obligations to maintain client confidentiality. This means that they are not allowed to disclose the information shared by a client during therapy sessions to anyone without the client's explicit consent.
However, there are some exceptions to confidentiality, and these can vary depending on the therapist's jurisdiction and the specific situation. In situations where the client's safety or the safety of others is at risk, therapists may be required by law to breach confidentiality. This is usually the case if the therapist believes that there is a risk of harm, such as the client being in immediate danger of seriously harming themselves or others.
If you are concerned about your therapist sharing information with your parents, it's essential to have an open and honest conversation with them about confidentiality and any specific concerns you may have. This will allow you to understand their policies regarding confidentiality and what circumstances might lead them to break confidentiality.
Remember that therapists are there to provide support and help you work through difficult emotions and challenges. Sharing your feelings and concerns openly with your therapist can lead to a more productive therapeutic relationship and better outcomes for your well-being. If you're uncomfortable discussing self-harm directly with your therapist, consider expressing your concerns about confidentiality first to explore their approach to handling such situations.