My mic might be bugged

Somehow, someone joined my xbox party and either bugged the xbox party or my headset or my xbox. Possibly even my cell phone, and so I know this because someone who didn’t even join the party somehow heard my conversation with me and my friends. I was
also broadcasting the entire time but I had my mic off. I do have the mixer app installed on my phone. Also the person implied that they had been listening through my phone. So, is this possible and is there a way to fix this?

:)