The night I was supposed to spend the night with my girlfriend, I grew frustrated because she insisted on using condoms, ruining the mood. Unbeknownst to me, her older sister was secretly watching us have sex up close. The next day, while my girlfriend was asleep, I met her sister again. Amid an awkward atmosphere, she flaunted her big tits and seduced me, openly offering creampie sex without protection. Though I love my girlfriend, I couldn't resist the horny older sister's advances—my excitement fueled by thrill and guilt. When my girlfriend caught us, I was too overwhelmed with pleasure and ended up shooting multiple creampies into her sister anyway!