"Ohhh," I whimpered. "Oh Mark.... Ohh yes!!"

I squealed in delight as Mark slipped two fingers into my pussy from behind. I moaned and heard him let out a sigh, as his fingers made a wet sucking sound as they pumped in and out.

"So fucking wet." Gary said softly.

I focused my eyes on him and saw that his hand was moving faster across his crotch.

"Oh, oh yes oh harder!" I moaned.

Mark began thrusting his fingers faster and I started to groan continuously as he finger fucked his sister's needy little pussy. Leaning over, I let my head rest on Mark's shoulder while I wrapped my arms...