17 has to prove himself.

After kissing her brother fiercely android 18 pulls back to look at him as she answers his question.

"Well if you want to prove to me that I dont need anyone else then you better get started. If you dont convince me right now then I'll never have sex with you again."

17 was surprised at his sisters reaction, sure she had been mad at him before but she had never threatened to cut him off. What scared him the most was that she was stubborn rnough to do it. 17 didn't waste any time then he immdeiately started kissing 18 again, this time he pushed his tongue past her lips and into her mouth. 17 licked his sisters tongue as he brought a hand up to massage her tits through her shirt. Grabbing a breast in each hand he began softly massaging them. 17 pushed her jacket off her shoulders and down her arms he then grabbed the bottom of her shirt and lifted it up and pulled it over her head. As he did this 18 kicked off her shoes and pulled her pants down. 17 stepped back to admire his sisters beauty. Standing there in only a set of black panties and a matching black lacy bra 18 was the most beautifull woman he had ever seen and the only one he wanted to fuck. Walking back to her he ran his fingers over her nipples through her bra making her gasp at the soft stimulation.

"Oh! Well thats a good start 17. But you had better keep going."

"Don't worry sis, when I'm done you wont ever want to fuck anyone else ever again."

17 then tore off her bra and panties with one quick motion.

"Hey bonehead! I liked those , youre going to replace them you know!"

17 didn't respond he just leaned forward and took one of 18's nipples into his mouth and began sucking softly. He knew his sisters nipples were sensative and that she liked a gentle touch to her breasts so he caressed her breasts while he sucked her nipples. Running his fingertips all over her tits and caressing them while he teased her nipples with his tongue.

"O.k. thats better but it is still not nearly enough 17."

"I'm just getting started 18." 7 said with a smile. As he continued to suck and fondle her breasts he reached a hand down to her pussy and started rubbing along the slit. 18 was already dripping wet from her brothers attention. 17 knew that despite her anger 18 loved having sex with him, they hade fucked often enough that he knew what she liked and tonight he was gouing to do it all in spades. He stopped fondling her tits altogether , although he was still sucking and licking her nipples, and moved his other hand to her pussy and quickly shoved two fingers inside. Pumping them back and forth with both super speed and super strength, while 18 liked it soft and gentle with her breasts her pussy loved a good hard fuck and 17's fingers were doing the job nicely. 17 wanted to make his sister cum more than she ever had before so without much foreplay 17 took 18's clit inbetween his thumb and forefinger and pinched sharply. That sent 18 into instant orgasm, her pussy clamped down on his fingers like a vise and she had to grab his shoulders to stay standing up as her entire body shook from the orgasm. 17 loved the feel of his sisters juices flowing onto his fingers and when her orgasm was over he licked his fingers clean savoring every drop of his sisters cum.

"That was great 17 but like I said earlier not nearly enough."

"And like I said earlier, I'm just getting started."