HOMA-061 - Her sister is seducing me! Sneaking behind her back for some heart-pounding creampies

I love my girlfriend, but we're in a rut. Her little sister Emi keeps clinging to me whenever I visit. I thought she was just being sweet, but she's a total nympho! Her innocent seductions are driving me wild. It turns out she's even sleeping with her mom's boyfriend... It's morally wrong, but there's no turning back now! I can't stop creampieing this insatiable girl.