Beth knows

Beth's eyes are locked on Emma's sodden pussy for a few seconds, widening as she combines Emma's flushed face, her juices coating her thighs and then....

"Wait a minute... Is that spunk on your foot?"

Emma freezes. She wants to cover up, wants to deny it all, but she's instead frozen with fear. You watch her trembling, with her skirt hitched up she's basically completely naked in front of her friend, and finds herself unable to talk.

"Have you been fucking someone in the library?" Beth presses further, stepping closer and looking down at her friend.