A few weeks ago me and my girlfriend had sex at my house when no one was a round. At night when my GF is tired she acts like a drunk person, always telling the truth. Her sister asked her if she had sex with me and my GF said yes. Her sister told her other sister and that sister is now threatening to tell her father. I don't know what I should do. I need help please

if you want to reach me here is where:
Gmail- Meanset12@gmail.com
Discord- Aktioo#7213