I pleasure myself while watching my stepsister's friend and she emits seductive moans. I stimulate her with my fingers, followed by her reciprocating

I was lounging on the couch when I heard enticing moans coming from my stepsister's room. Out of curiosity, I peeked through the crack and saw her friend, Susy, pleasuring herself. I found it incredibly arousing and decided to join in. I asked her to keep quiet and remain still, while I sat behind her and began to touch myself. Soon, I reached a state of arousal and gently caressed her small, firm breasts. She responded by spreading her legs, inviting me to continue. I obliged, exploring her wet folds with my fingers. The sight of her writhing in pleasure only fueled my desire further. Before long, I was lost in the throes of ecstasy, my fingers moving rhythmically inside her. The experience was so intense that I had to withdraw, leaving her breathless and satisfied.