"Easy sis I can't..."

I stopped and looked up at him.

"Don't worry about it little brother your nasty big sister wants to suck you off in the shower so you just enjoy."

"Oh damn." Mark whispered then moaned again as I resumed my rapid sucking of his cock.

It didn't matter that Mark had already cum with Krissy and that I was going to get him off now. My little brother would still be able to fuck his needy big sister in a little while. Christ one night a few weeks ago when the folks went away we had done it five times. I started taking Mark deeper and...