You've been fucking your daughter Lola for years, but now she's got big tits and a little hair on her pussy you're not that interested in her, especially since you have another younger daughter to satisfy your sick, perverted desires!
The thing is though, you've trained Lola to crave her daddys cock and she wants it so bad that she won't stop at nothing to get it. When you come round she tells you she knows you've been fucking her little sister and that she's jealous. You said no to her last night then went straight into the other bedroom and that just won't do! Lola will be having your cock whenever she wants AND you'll be having a threesome with both daughters so she can eat her little sister out. What have you done daddy, created a little family fun obsessed monster ;)