Unable to bear seeing his younger brother dumped by his girlfriend due to premature ejaculation, a kind-hearted big-breasted older sister strips down and starts training to improve his condition! Starting with slow insertion, gradually increasing the pace, then high-speed hip thrusts stopping right at the brink of orgasm!… But the plan falls apart as her younger brother can't hold back and explodes inside multiple times. From that day on, daily premature ejaculation improvement and ejaculation management! Can he improve his condition by enduring sudden switches from slow to fast grinding in teasing cowgirl position?
