Having Sex with My Chubby Muscular Little Brother

Because the chubby muscular little brother didn't have much sexual experience, I let him sit on top to slowly adapt first. As his anus continued to spasm, milky white semen flowed out from his urethral opening. Under my patient guidance, the little brother quickly learned to prolapse, and it got more and more intense. We went from dawn to dusk, and finally exploded inside the little brother's anus. The little brother's prolapsed anus turned into a beautiful cream-filled cream puff.