Two teen best friends, Savannah Sixx and Gianna Dior, are hanging out in Gianna's bedroom, giggling and having fun. Their happy attitude is interrupted when Gianna's sister Scarlett Mae barges into the room, telling the girls that she's having her boyfriend over and they are not to go near her room. The girls tease her, which annoys her. Scarlett gives them a final warning and then slams the door on them, leaving the teens to giggle and roll their eyes at her attitude.Later that afternoon, the teens begin to hear faint rhythmic squeaking and moaning coming from down the hall and wonder what Scarlett is up to - Savannah suspects they're having sex. Gianna isn't sure, but Savannah reminds her that they're both 18, and Scarlett is even older than them, so she's probably not a virgin! Savannah suggests they go spy on her - Gianna questions why but Savannah convinces her, saying that could even snap a pic of it. The teens sneakily tiptoe down the hall to Scarlett's room. As they approach, the bed squeaking and moaning sounds get slightly louder, although they're still muffled behind the door. The girls stop at the door and shush each other, before Savannah quietly turns the knob and pushes the door ajar. The two teens gather around the door-crack to look in.As they watch, quietly snicker, and exchange looks at each other, the girls begin to get sexually riled up at the sight and snap a quick pic with the phone camera. They hurry to close the door, scared to get caught.The teens sneak back into Gianna's bedroom and gently close the door. Gianna makes a half-hearted suggestion that she guesses they should get back to homework, but neither seems able to shrug off the horny feeling still lingering.Savannah suggests they masturbate to get it off their mind. Gianna is shocked and hesitant, but her friend eventually convinces her. They slowly start to strip down to masturbate, Gianna clearly the more unsure of the two but Savannah encouraging her. The masturbation is slow and hesitant to start but as the girls start to warm up to the experience, they begin to get more comfortable around each other.Savannah suggests they look at the picture they took as they masturbate. Savannah sneaks glances over to Gianna's pussy when she thinks Gianna isn't paying attention, and also some worried glances up at Gianna to make sure she didn't catch her looking. Eventually Savannah gets bolder and offers to 'help' Gianna, who is too caught up in lust to object. She begins to finger her friend.Spying on sis has these teens all hot and bothered, and there's only one way to release THAT kind of tension!