On a day when our parents are not around, my college-aged sister invites her friends over for a girls' night at her house. The friends get so excited talking that they miss the last train, so they all end up sleeping together in a pile. I got curious and took a peek... I saw her sleeping defenselessly, her panties and breasts flashing everywhere! My virgin dick is fully erect and I'm cumming like crazy! When my sister's friend noticed, she got close to me with a grin on her face... She must have been frustrated because she kept asking me for sex and I forced her to cum inside her. Even though my balls were empty, I still had a good time!