Kayla’s boyfriend opted for the new, experimental procedure in which a penis was grown in a lab, to his specifications, from a sample of his own DNA. The 18 inch monstrosity, thicker than Kayla’s upper arm, was then grafted on in place of his original penis with the latest technology knitting nerves together seamlessly.
He loved his new cock and said that it even felt better than the original when he came. Kayla thought it was great that her boyfriend had such a huge cock now, though he still insisted on pounding her tiny ass almost every night.
The pain usually left her drooling, unconscious, and moaning in her sleep for the night. However, she could easily brag to all her girlfriends that her boyfriend had the biggest, baddest, meanest cock and could even show off her gaping asshole to prove it.
She did worry when one of her friends said that her own boyfriend was going in for a 22 inch replacement cock. Kayla would have to ask her boyfriend to get an even bigger one and she wasn’t sure she’d be able to handle it… but she’d still have to beg him to get it.