Recently taught by my cousin onee-chan the "pretend sex" game. I don't fully understand it yet, but my heart races and excitement builds inside me. For some reason, I keep getting more and more hooked on this game, and now I beg her to play pretend sex every time I see her. We kiss deeply, our tongues intertwining, and I caress and massage her big breasts. Seeing her melt with a helpless expression, she straddles me and starts rubbing my cock. Onee-chan whispers, "It's our secret from Mom and Dad," gently enveloping my feelings. I know this is wrong, yet my heart pounds wildly with forbidden thrill.