She wanted to breed him with her own cock

Sarah groaned as she came. She really did not want to have to show both of their moms what she looked like when she came. But at the same time she was not going to just let her dick go without cumming in a hot throat! She let her breath go as she sighed and leaned back she knew that she was going to have to fuck his throat again but for now, all she wanted to do was to get a bite of dinner then maybe she could go back to her room with her brother on her dick and let him know that she was still the futa in the sibling relationship. The two siblings both had a moment of starring into the other eyes before Sarah slowly let her brother off of her cock. She blushed her heart still beating erratically out of her chest and threatening to burst at a moment's notice! Her cheeks turned a bright shade of red as she just remembered how she had been skull fucking her brother in front of their parents! She coughed as her mothers despite having just saw their son face fucked by her did not seem to pay much attention let alone mind it at all. As the two of them finally got apart the mothers looked once at their direction.
"Are you two enjoying the other?" Rochelle asked as she sipped on a cup of milk as Sarah blushed.

"W-we are just enjoying each other...."
"I think I need help..." Her brother gasped as he tried to stand up Sarah helped him up as he groaned in pain Rochelle frowned as Summer blinked.

"Now daughter if you do not give the proper care for your male that is not what I call a good mistress. So you should make sure he is ok. That means you need to pace yourself."
"I-I know!"
"Good. Well then what are you going to do?" Rochelle asked as Sarah gulped as she helped Vince up as she pulled him to a chair.
"I... I'm going to take him up to my room to see if I can help him relax!"
"Relax?" Rochelle asked a clearly disbelieving look on her face as Sarah gulped.

"Y-yeah?"
"Oh you are just going to try to knock your brother up! You better be able to breed or I'm going to have to punish you for that!" Summer said teasing her daughter flushing gripping her brother as he grunted.

"I... I don't think I can move, can I get some water?" He asked as Sarah gripped a nearby glass and pushed it to his mouth and forced it back as she tilted his head back and forced him to gulp it down roughly making him heavily choke on the drink.
"T-there, I'm trying to help!"
"If you want to fuck your brother do it proper. If you are not here to get a child do not cum inside of him. Or else." Rochelle said as Sarah gulped as she started to try to take her brother from the table not sure if she'd make it to her room before one of her mothers or worse someone else tried to interfere sure they were alone in their home but who knew what could happen when your brother was one of the hottest pieces of ass in school with almost all of the futas of his ear and below after his ass! She'd be lucky if no one broke down a window to fuck him in front of her before she could get her dick inside of his tight ass!
"I'll do that! I'll only cum inside if I want kids! N-not just because It'll feel nice.... And it'll be great...."