This is what you were waiting for!

Kary leans in and lets loose. Huge gobs of cum surge into your stretched belly, filling it out quickly. Then as quickly as it came, it stopped. Kary rests her hands on your shoulders.

“That’s all you got? First time fucking your brother-“

Then you feel it. Kary’s big cock getting bigger. You quickly try to get off but it’s too late. You are pinned to Kary’s crotch as her growth spurt hits. Most of that fatty junk food goes straight to her fat dick fully inside your butt. Your hips feel pressure from the inside as they are assaulted by the widening penis of your sister. Your feet are knocked out from under you as Kary’s balls swell after landing on the floor.

“Remember, you love your fat sister and how fat she is,” Kary reminds you.

“I-I do, Kary! This dick is amazing! I thought I had conquered it, but then now it’s growing!”