Both the girls laughed as he fumbled over his own words.

Melanie continued, "Yea, I would say about 7 months. Ever since I turned 18, remember?" She smiled in response to Katie, who was now sitting Indian-style on the lounge chair next to them.

Robby's mind was not focused on the conversation at hand however, but on the pillows he had been so lucky enough to use as a headrest. He could only admire his own craftsmanship. Growing his sister's breasts to such a size was not something he could let go unappreciated for. In fact, they had out grown the largest breasts in Denise's clique: Katie's!

His eyes locked onto Katie's perfect orbs once again as the two girls continued to mingle unknowingly. Rob felt his mind slip, but this time he didn't struggle against it. He let the weight of his eyelids pull him deeper into his subconscious as his mind attempted to alter the girl in front of him. First, he thought. "her breasts..."

bigger...Bigger...BIGGER!!

Her shiny young breasts glowed in the sunlight as they swelled slowly in the middle of the conversation. Her arms lay akimbo in her lap as her breasts began to cover more and more of the view in between, swelling bigger and bigger...

"So I told Daniel to go get it herself and she was like, nuh uh!" Katie's body shook from the gesture, sending erotic jiggles and jostles of all kinds all around her beautiful bust. It felt like Rob managed to just go flaccid when his dick grew rock hard once again. Damn her...

"No way! Did you tell her off?!" Melanie gasped in shock, obviously immersed in the conversation.

Rob grew a wide smile as he peeked over Melanie's side-- since her shoulders were too high to look over now-- and took a mental note of Katie's figure. He rested his head against his ex-sister's warm back and closed his eyes, picturing the beautiful blonde on the lounge chair. He felt his penis twitch from the vision. This girl was absolutely stunning!

Ever the slightest bit taller, he imagined, inching her up.

He peeked over at her again just as the changes took effect! His penis throbbed forward in his swim trunks, pushing the material against Melanie's lower back.

A little more, he reasoned, watching as her form elongated in his mind slightly. He manhood stood painfully rock hard now, poking Melanie in the back. Rob truly hoped she couldn't feel it.

Once more he stole a quick peek at Katie as she moved her arms around, talking. She grew.

Rob watched as her height finally appeared to match that of Melanie's and that sent Rob off the deep end. Hi swim trunk's meshing gave the slightest sensation that something was cupping his jewels. He exploded inside his swim trunks violently as his penis involuntarily flexed over and over again from the reverberating images in his mind. These two well endowed teens were just too much!

The girls got up and began to gather their things, sliding Robby down onto his feet in the process well before he was ready.

"You alright there, Robby?" Melanie took a hold of him by the shoulders, trying to straighten him.

"I think the poor guy got a little too much sun." He heard Katie inquire just as his vision completely blacked out.