I grabbed a trashcan with a bag I held in front of her. She barfed first. Once I saw that she had gotten it all out of her stomach, I quickly tied the...bag off to stop the smell.I triple bagged it.I heard her start to pee and then her intestines gurgling with what was to come.“I remember having to pee so badly that I didn’t care who saw me, but pooping was always something I wanted to do in private. You aren’t going to barf anymore, and it will be a little while before you finish pooping it all. Next message came immediately again, "Guess you've never seen Red Dwarf then?" The conversation continued with him telling me he was bored and me suggesting a bunch of things he could do, all of which he made excuses as to why he couldn't until eventually I lost my temper and told him to go and have a wank if he was that bored.Weirdly that didn't seem to offend him and our conversations continued over the next few weeks with me finding him less annoying and more interesting as the days went. As I started to get close to cumming I closed my eyes and tilted my head back for a minute or so and then as I started to cum I opened my eyes and looked towards the bathroom and to my surprise my step-sister was standing there peaking through the 1/2 closed doorway to the bathroom with her fingers of her one hand obviously in her pussy watching me as I came all over myself. As our eyes met she gasped and then slammed the bathroom door shut and I just continued to keep stroking my cock like. The feeling of another dollop of hot cum hitting her privates sent her into a second orgasmic wave. "Uhh...uhh...uhh..." she moaned, her slim body shaking, overwhelmed with pleasure at this novel, forbidden sensation."Ohh wow..." he gasped as he fell back on his heels, utterly spent. That had been a strong one!Finally, she came down from the most powerful orgasm of her young life and relaxed, her legs splayed, a silly grin on her face."Shit..." her brother said as he went to grab the box of.