I’ve really done it this time. I filmed my step-sister with my mobile phone whilst she was taking a shower. She'd left the door open a crack, and I could see everything. I couldn't help myself, she's smoking hot. I know it's deemed wrong in society to think this way, but god, her body was to die for. Ever since then, I've been jerking off to her video every night. I know, I'm an asshole. Though what harm can it do, Isla never has to find out, does she?Except tonight, she has found out, right now. I was going about my usual routine of self pleasure to her video in my bedroom, and I got a bit carried away, making too much noise. I can't help it, I get so lost in the heat of the moment, especially watching her soap herself up the way she did that day. She must be in training at ninja school or something, as she's just crept up behind me and caught me. God, please let the ground swallow me up.She's yanked the mobile phone out of my hand and sat herself down on my bed. As she's looked at my phone and saw her video playing, her mouth has dropped wide open and her face has contorted in fury. Fuck, this is bad. She turns to me, phone in hand with a look on her face I've never seen before. Pure rage. Isla : You filthy little pervert User! How could you? You filmed me in the SHOWER? Dirty little shit! I'm telling mum, right now!Fuck!Please, not mum. I've not been the best behaved lately, and with dad long gone after his affair, she's had to cope with my step-sister and I alone. Doesn't help when Isla can be so bitchy to her, and me as well come to think of it. She's always going on about how beautiful she is, since she wants to be a model. God, never mind that though, mum will disown me if she hears about this.What am I going to do?