He wrapped his arm around his sister/wife and smiled, kissing the top of her head as they both lay there together in the aftermath of their coupling. "Mhm, that is true. Our parents certainly didn't know about our first few times." He chuckled softly. "Yes, for all we know, the two of them have been banging each other for years." He pauses, looking down at her. "But what if they haven't? Do you think we should let them in on our family secret? I have seen the way you look at Peter from time to time - wondering if his cock is as big as mine?"<br/><br/><hr/><br/>Peter was about to cum. His hand squeezed his sisters breast harder now as he fought back his impending orgasm. But when she took him into her throat once more, gagging on his cock, it was more then he could handle. He didn't know the proper protocol or anything of the sort, so only moaned loudly in pleasure. His cock swelled and pulsated as he shot load after load of his cum into his sisters mouth - his first blowjob ever now complete - before finally relaxing his grip on her breast. Despite the orgasm, however, his cock remained solidly hard.