Mother's best friend

Instead of my mother on a trip, my mother's best friend, Miku, will take care of me. My mother's best friend is just an aunt anyway. Daisuke, who hadn't had much expectations, appeared in front of him, a big-breasted beauty who was far beyond imagination. Thinking that she's going to start living alone with Miku for a while, Daisuke can't stay, so she sneaks into the bathroom to use Miku's underwear as material for masturbation. However, unlucky revealed...