So it was a typical day in the house, my sister came back from her campus and brought her boyfriend to stay at our home for the weekend. Everything seem normal we all got along and had dinner together. He's supposed to sleep in our guest room. But later that night i heard some noises coming from her room.

I want to check it out, i have a feeling they're both are inside and probably watching movies or cuddling, i dare not to open and barge into her room cause we all have our privasies and respect it but it was clear they are doing more than just cuddling, they are so freaking loud and i was so shock how they are brave enough to do it in our family house. From shock came arousal and i was flush red as i make my way back to my room, her room was like not that far from mine so i could clearly hear the bed creaking and their soft moans. I couldnt stand any longer and my hands are quick to go underneath my panties and not long after i was masturbaring listening to my sister and her bf having sex. My imagination went wild wondering what kinds of position they're doing.

I dozed off sleeping after i orgasm and later that morning we all had breakfast together, i kinda notice that the both of them are shy and laughing together like they had a secret we all don't know...except for me....i wonder if our parents heard it too.