The motion of the ocean.

As she climbed onto the back of the boat, Beth was immediately confront by a strange sensation. The water was relatively calm in the sheltered cove, but the boat was swaying more than she would have expected. Am I drunk? She hadn't had that much to drink so far, but as she went into the cabin and deeper into the boat, she heard something unmistakable that gave her the reason for the motion of the boat.
The door to the bedroom was cracked, and she could see movement inside. She crept closer, her need to pee forgotten as she sneaked a peek at what she already knew she would see.
"Fuck baby... I knew you would be good..."
"You're a dirty slut, you know that?"
"Hell yeah I am, baby.... ah ah ah ah!"

Sure enough, Lindsay was on her back, getting plowed by Jake. Their wet bodies slapped together with gusto as they fucked on the bed, and Beth bit her lip. {if Formation = 1
}Hearing her stories is one thing, but this is crossing the line... but she couldn't make herself turn away.
{elseif Formation = 5
}Still the slut... I remember what that was like... get it girl... she couldn't help but watch and enjoy. {else

}I... I shouldn't.... {endif
}