She gives him a blowjob

I watched breathlessly as Becky got on her knees in front of her brother neither said as word as she slowly stroked him. She leaned forward painfully slowly. Sam moaned softly as he felt his sisters breath on his shaft. Becky plased her tongue at the base of his cock and began to run it along its length. Sam quivered with pure desire. I know he must want to just ram himself deep into her. I was enjoying watching him squirm. After having him dominate me all day it was a relief to find out that his sister was very much the one in charge.

Becky was older than Sam, in fact we were in the same year at school. We had never really seen eye to eye on a lot of things. I wouldn't say that we we hated each other but we were definently not friends.

As she reached the tip of his penis a small bead of precum leaked out. Becky saw it and lapped it up eagerly with her tongue. I guess it hadn't really sunk in yet but I realised how wrong this whole situation was.

"This is…so hot" I said quietly.

"I'm glad you're enjoying yourself " Becky laughed, before taking Sam into her mouth.

She leaned forward and took the tip into her mouth. She played with it in her mouth as Sam continued to squirm. She must enjoy teasing him.

Sam slowly placed his hands on his sister head and tried to gently push her down onto his shaft. However, she just swatted his hands away and sat straight up.

"Oh no" she said "we're doing this at my pace"

"C'mon sis, I really need to cum" he protested.

"Nope. You're lucky you're even getting this after what you did. I could barely believe it was you when I saw you fucking Ashley at the window"

I guess she must have been watching us earlier.

"Was I just not good enough for you?" Becky asked jokingly "how'd you dven convince her to fuck you?"

"I kind of…blackmailed her" he said

"Oh, now it makes sense. So you decided to fuck her for the whole neighbourhood to see? I never knew you were so daring. We might need to try a few new things"

"Yeah, but can we get back to the situation at hand" he said

"Well, maybe" Becky said as she gave him a few slow strokes "but first you've got to do something for me"

"Yeah, sure" he said as she continued to slowly stroke him.

"I'm guessing you still have whatever you're blackmailing Ashley with. See as you got her over here to fuck you"

He nodded. I didn't like where this was going.

"So I'll let you cum now on the condition that you…extend Ashley's services to me as well"

"Whatever you want" he moaned as Becky began stroking him faster.

"Wait…" i said

"Sorry babe" Becky said "you don't get a say"

Without another word, she leaned forward and took all of sam's cock into her mouth. Her long, loose hair flopped forwards covering her face as she bobbed up and down on his shaft. She made cute gagging noises as Sam hit the back of her throat.

It was too hot. Watching Becky deepthroat her own brother. I began to finger myself and tried not to think about the fact that I was now their family sex toy. I have no idea what they are going to do to me.

I could see form the look on Sam's face and from his frantic sex noises that he was about to cum. I was going to watch his sister swallow his load.