In the past you've tricked your sister by locking her in her room while she's desperate to pee and filmed it all for your use. But she never seems to learn. Today she brought her boyfriend over and they had sex. He asked her to hold her pee before they fuck so that she has an amazing orgasm. After they fuck she really needs to use the bathroom, but the door is locked again. She becomes frantic. She has to pee so bad but she can;t pee on the floor or anything. Despite her boyfriend asking her to hold her pee, he finds the site of women peeing disgusting. She doesn't want to shock him so she holds it in despite feeling like she's going to explode. She can't hold on for much longer. She has to use all the willpower she has to hold it because its to the point where one wrong move will make her burst. But she can't do it. She moves and starts spurting all over the carpet in a big loud burst. She cries as she pees powerfully on the floor because of how embarrassed she is. She cries and apologizes. She doesn't even notice the hidden camera this time.