Kiyoshi, isn't it about time I held a grandkid? Mother-in-law blurts it out, I'm floored. Family hot spring trip meant to be fun, but she urges me to knock up my wife on the sly... Per her demand, I abstain for a month, hyped for the trip, but wife won't fuck! Pent-up lust boils over, catch her bathing... That ripe, busty body snaps my sanity. A month's worth of horniness erupts, pin her in the springs and pound away. One load ain't enough, whole trip wild creampie frenzy, can't stop thrusting. She moans no but screams in ecstasy, belly flooded with cum. Now she's knocked up for real, wife can never know this filthy secret...