Mattifact

And I found my wife's vibrator. They are having 'a talk' about it now.

Update: tl;dr version - personal boundaries were violated for both parties. Everyone agrees (mother and daughter, as I was not involved in the talk) to respect privacy moving forward. There was no shaming. Now there is better dialogue about masturbation and sexuality between them.

I still feel awkward but pretend I know nothing for my kid's sake.

For clarification, it was put away and took some rather invasive snooping to find the vibrator.