Justin looked as his little brother's crotch finally stopped growing and took in the sheer size of what he created. "Justin, what happened? My undies are really tight." Tommy commented and asked his older brother. "Im going to tell you a secret but you cant tell anyone else ok?" Tommy nodded at his brother question. "I have magic powers and I used them to make our penises grow big like a grownups." He couldnt tell his brother everything in case he wanted to try the ring himself or even steal it. "That's awesome!" Tommy shouted before quickly being shushed by his brother. "We dont wanna wake dad up." Their father was a deep sleeper and had a room on the other side of the house but Justin didnt wanna take any chances.
"Can you do more magic Justin? It would be so cool to see it in action" Tommy asked. Justin thought to himself before deciding to go through with it. "I have an idea." He placed Tommy in his lap before closing his eyes and focusing on the ring. Suddenly he felt something moving in his lap, and could feel his baby brother's butt start to grow bigger. It slowly began to fill up his tight underwear before bursting off his little body. His little butt was only the size of a 13-year olds, but it wasnt done yet. Tommy climbed out of his brothers lap and laid on the bed as his ass continued to swell bigger and bigger until until he had two basketball sized ass cheeks bouncing for a backside. As the growth finally subsided, a thick layer of hair quickly grew to cover his new manly ass. "Wow, I might have a bigger but than daddy. And its way hairier." Tommy pointed out. Justin began to grab and feel Tommy's new and improved ass and looked down at his baby brother. "you make a good point, Dad could use some upgrades. Or we could stay and have some brother bonding with more magic."