My girlfriend and her sister have opened a Youtube channel "swimsuit sisters". The views are quite high and both are quite popular as well. Today I was asked by my girlfriend to help me shoot a video and it was also the first time I met Sumire. From the first time, I was attracted to her hot body and her skimpy swimsuit. After filming, my girlfriend and I went to her room, and we had sex right here. Sister Sumire also secretly watched us, and when I went downstairs she used her big breasts to seduce and squeeze out my sperm. In the evening, she continued to sneak in and demand to fuck me even though my girlfriend was sleeping right next to me! She even allowed me to "play naked" and cum in her pussy, which my girlfriend never allowed! And from then on, we kept secretly fucking each other every time we got the chance. That was until I was about to go to France to study abroad with my girlfriend. But everything didn't end easily like that; Sumire invited me to have one last fling, and that last time was discovered by my girlfriend...