Well she's technically not violating any commandments so she should be safe.Can horny sister go to heaven? I hope so, a sequel where horny sis pervs all over heaven would be good.
The boys were part of the "The D makes it better" squad eh
Never try to take Mikhail from Sister.
Seems like Sister isn't a dirty fujoshi. Ah, well...She's right sister, you should have let it play out for a bit longer!!