Today I got home earlier than usual and when I opened the bedroom door I found myself in front of a truly unexpected scene! My boyfriend was in bed with his step-sister! Excited by the situation, I started spying on them and I heard they were talking about sexual topics. At that point she started giving him a wonderful blowjob while my boyfriend touched her everywhere! I couldn't resist ... I started touching myself until cumming, the same moment my boyfriend cums in his step-sister's mouth