You decide that Emily will be better off as nothing but cum instead of as a squirming little slut in your ballsack. Soon you begin to stroke your dick and slightly concentrate on compressing your sister within your ballsack. As you start to digest your sister, you grope and fondle her snall but perky breasts as she softens within you. She tries to call for help but their muffled screams are drowned out as she is digested by you. Soon enough the detailed outlines of your sister starts to soften, loosing their detail and her movement slows until she goes still inside you, sventually becoming nothing but gallons of cum inside your ballsack. Precum comes out slightly as you marvel at the notion of churning away a entire person, even more so that such a person was your own sister. Now comes the notion of what to do with the remains of your sister. You could find someone to pump the remains into a slut, or just cum her out in the shower, removing any evidence of your deed.