Best Friends Step-dad Sent Me A Unsolicited Photo Of His ???? To Me But No One Believes Me. Can I Legally Show Them The Photo?

*** EDIT *** Thank you all for taking the time to respond and helping me. I appreciate it. ????

Australia

Title pretty much says it.

My best friend and her mother have been like family to me for over 10 years now, but I've endured a lot of emotional pain from this situation because no one believes me and her mother has verbally abused me and thinks I'm just attention seeking.

I have the proof but is it illegal for me to show them? Even though I never asked or wanted him to send the photo to me in the first pkace. They are the type to sue or press charges on people.