Do I have to tell my therapist about SA as a child?

I just finished a session and they was asking about my parents, they asked me if there was anyone who ever let me down, and at the time I guess I did not feel let down, its only as an adult I realise it was wrong. I kind of skipped around the question because I've never spoke about it to anyone and we moved on.

The therapy is for social anxiety, and I feel like I should tell them but I also don't really want to talk about it, am I sabotaging the sessions by not talking about it?