"Oh, shit, Sis!" he whispered as she began sucking gently on his delicious prick. "That feels so fuckin' good!"

Moving her mouth up and down over his straining cock, she began a slow sucking action that had him writhing all over the bed. Her head was soon bobbing faster and faster as she sucked more passionately on his big delicious prick. Kirk's entire muscular body was trembling and jerking from the heavenly sensations being induced by the sweet, soft mouth of his little cock-sucking sister.

He could feel his climax building deep in his balls, and, as his orgasm drew closer, he unconsciously grabbed the girl's head and shoved her sucking mouth down tighter over his throbbing cock-shaft.

"Jesus Christ!" he roared as he started shooting his wad.

Marci's entire body shivered with delight when his hot cum started gushing into her mouth. Not wanting to miss a drop of his delicious fuck-cream, she desperately sucked and swallowed until she'd drawn every bit of cum out of his slowly shrinking prick. When Marci had licked and washed his limp cock completely clean, Kirk kissed her softly on her lips and left the room.

CHAPTER FOUR

From that night on, Kirk was finger-fucking his little sister two or three times a day while she was sucking him off.

"Kirk," Marci whispered to him one afternoon when she was up on his bed with him.

"You've fucked lots of girls, haven't you?"

"I've had a few."

"Is fucking fun?"

"Of course it is."

"Would I be fun to fuck?"

"Shit, yes," he said, grinning.

"Then will you fuck me?" she excitedly asked, her eyes glowing with lust.

"I wish I could," he sighed. "But that would be impossible."

"Why?"

"Because you're my sister."