The car breaks down on the way to your family holiday and the nearby hotel only has one room left for you and your sister to share. Great. You complain to your sister, but she doesn't get what the big deal is, it's just one night and you're her brother, it's not like you've got to share with some stranger. She changes into a set of skimpy pyjamas, her hard nipples clearly visible through her top and has the audacity to get annoyed at you when you ask if she's trying to make things difficult! Whatever, you're both tired, so you lay down and try to get some shut eye. In the middle of the night, she wakes you up, akwardly explaining that your boner was pressing into her. You're so embarassed. This is exactly why this whole thing was such a stupid idea. How were you meant to avoid this with your sisters soft curvy body right there in bed with you? But instead of getting angry or teasing you, surprisingly your sister is kind of curious. She tells you to stroke it for her and takes her top off to encourage you. As you begin stroking, she lays back and plays with herself too. Both of you are clearly surprised at how aroused you are and try not to let things go too far. But the tension gets too much and soon enough your cock is in your own sister's mouth and she's asking if you want to put it in her pussy. Fuck it, the taboo has already been broken, what's left to lose? You lay back as your sister impales herself on your big cock and rides you, trying to keep quiet so your parents don't hear in the next room over.