"No – don't stop that," Les gasped. Roberta's head bobbed back and forth a few times. Amy clearly heard the sound of wet cock-sucking and saw her brother tremble with pleasure. Then Roberta was standing and pushing Les back towards the big waterbed.

"Kid?" Roberta said. "Hah! All day long, men were trying to get close to her and pick her up and…"

"You keep them away from my little sister!" Les snapped – and then groaned. He'd lain back on the bed, and Roberta was kissing and licking her way up the insides of his long legs. Her firm, ripe ass was waving voluptuously in the air.

Roberta shifted to kiss Les' balls, and Amy saw his cock. She felt her pussy juicing up as she gazed at it. It was beautifully formed – and huge, the biggest she'd ever seen!

"She's a beautiful young woman, Les," Roberta was whispering between licks and sucks at Les' ball. "She's no kid."

"Ahhh – yes, suck my balls!" he groaned – and then Amy was stunned as she heard her brother say, "You're right – she is beautiful… and sexy as hell. But that's all the more reason why we have to – ahhh! Yeah! Suck 'em, woman!"

Amy listened to the slurping – and then to Roberta saying, "I know you know it, Les. I saw that hard-on you had when you saw her come out of the bathroom in those tight pajamas! She turns you on, doesn't she?" Her hand was gripping his cock shaft and moving up and down. "Admit it – if she weren't your sister…"

"Oh, cripes…" Les moaned. "Shut up, and suck cock!"

Roberta obliged for long minutes, her head bouncing up and down, her lips lightly skimming the thick shaft of his cock – and then suddenly tightening as her cheeks concaved. She was sucking his cocktip for all she was worth – and that was plenty!

She freed the thick cocktip with a loud popping sound, and then resumed the conversation. "Yes, but if she wasn't your sister, if she was just a girl you met on the street…"