Girlfriend and her mother in hotel

If I remember correctly, story told by male who is sleeping in a hotel room with his girlfriend, her mom is in the opposite bed. She strips him and starts playing, he realizes the mom is watching and his girlfriend is doing it intentionally in front of her mother. After a show, he ends up having sex with the mom as well. Thanks for the help!

Sounds like Sierra's Amazing Mouth by ChancesAre.

That's the one, thank you so much!