how to tell daddy?

Hagar • 13, 🌺
My parents are divorced and I had my first period last year at my moms house. I'm not spending much time at my dad's house cause I don't like the family of his new wife and I didn't tell him that I have a PERIOD. Now we're in vegas only me and dad and I started my period now. And I have no idea how to tell him... any suggestions?