He wants to see how far she is willing to go.

Matt smiled as he looked at his sister and asked. “What are you willing to do to have a turn on my dick?”

Becca’s eyes went a little wide as she realized her brother wasn’t just going to give her what she wanted. She looked at him watching her with a cocky look on his face and felt herself grow angry. “Why should I have to do something for you? I’m a hot piece of ass. You should feel lucky I’m having sex with you.” She said vehemently as she glared at her brother.

Matt shook his head slowly as he said. “If you don’t want to deal, I have a willing slut right here who will do anything I want.” Reaching over he cupped Randy’s face forcing her to stop blowing him and sit up.

Matt didn’t realize he had made a mistake till his sister jumped on him. She had straddled his hips before he could even react, and by the time he got his hands on her she was already slamming herself down plunging his dick inside her. “What do you think your doing?” He yelled as he tried to lift her off.

Becca wrapped her legs around her brother’s waist and used his attempts to lift her off to help her thrust. She saw the frustration on his face after she let him push her back only to squeeze her legs and thrust him back in. She giggled maniacally and said. “I’m taking what I wanted little bro.”

Matt stood up and tried to get his sister to let go but nothing seemed to work. As they fought his struggling became more like fucking as his libido started to take over. Soon he was violently moving his sister’s hips as he thrust into her. “Take it you bitch!” He growled at her as she started to moan.

“Yeah I am! Fuck your slutty bitch of a sister!” Becca screamed and started to moan even louder.

Randy was watching Matt fuck the shit out off his sister with a little jealousy when she noticed the pen sitting on the couch. Getting a naughty idea, she picked it up and moved closer to the incestuous pair.