My brother and his wife are going on a trip, so I ended up taking care of my niece Mizuki. Mizuki has always been close to me, and she hugged me tightly when we reunited. In the living room, she also sat on my lap and snuggled close, happy. But unlike before, seeing my grown, cute niece made me unexpectedly get an erection. Noticing this change, instead of looking down on me, Mizuki smiled and pressed even closer. She then secretly inserted my penis and began to thrust slowly, making sure my wife wouldn't find out.
