That night we decided to sleep in the same manner as we had the night before; me on the couch furthest from the TV and him on the couch perpindicular to mine and a few feet closer. I told him that my girlfriend had swung by while he was at basketball practice. I told him we had fooled around a bit. I knew he was inexperienced when it came to girls so I asked him if he wanted to find out what a pussy smells like. I tossed his sisters panties to him and told him they were my girlfriend's that she gave to me that morning. He reached down and adjusted his growing cock. He didn't try to hide it under the covers or anything. He just lay there with his boner bulging in his boxers. He sniffed the panties a couple times then examined the stains in the crotch. Both of us pretended like it was no big deal. He tossed the panties back to me and commented on how tired he was. It was obvious that he wanted me to go to sleep and to think that he was also so I played right along.
Ten minutes later I was breathing heavy with my eyes closed waiting for him to put on another show. He said my name. I didn't answer. Through half opened eyes I watch him take his boxers off, stroke his cock a few times then get up and walk over to my bag and get the panties that he thought were my girlfriend's. His penis was veiny as he sqwatted next to the couch. His balls hung tight to his body and his pointy penis had some precum glistening in what little light there was. My cock grew to full size as I watched him plop back down on his couch and start stroking again. His sister's panties went right to his face and he inhaled his sister's scent. He licked the crotch and jerked his skinny dick until he came on his stomach and chest. He cleaned up and put the panties back into my bag. His cock was semi erect when he returned the panties. His balls hung farther down this time. My cock was itching for a release like the one I had just witnessed but I had to wait until he was asleep. When that time came I masturbated for a couple minutes before shooting my load all over the place. I wiped up my cum with his sisters panties and drifted off to sleep.