Gl with the new game Mike, but should really consider a title change for the next update. No one will really mind, it's like IHOP saying "Oh, that whole IHOb thing was just a stunt really, like New Coke, our bad."
Otherwise, even without actual incest, the title implies that the siblings will be "Cruel Intentions" kind of lewd - like competing/betting on the same character to have sex with, talking to each other about who they are doing, or going so far as not having sex with each other, but one watches while the sibling has sex with another character and maybe he/she joins those two in a three-way, but since they are having sex with them and not each other it's not incest.