I know the sisters are someone else's characters too, but I thought I'd just throw this idea out there.
I would go into more detail, but I'm not good with dialogue.
Maybe, Nancy and Natasha receive an anonymous tip about mutants living in the city's sewers.
The anonymous tip is actually from April O Neil, who wants revenge after losing the reporter of year award and ALWAYS coming third.
Nancy, her son and Natasha sneak into the Turtle's Lair and April and the Turtles are there to greet them.
Nancy and Natasha don't trust April and don't believe the turtles are mutants, but just guys in rubber suits.
The sisters decide to expose these "mutants" for the frauds they are and start by trying to remove their fake massive cocks.
They try removing them by using their mouths, tits and pussies, but nothing works
The turtles have fun fucking the dumb Boobitch sisters and April fucks Nancy's son, who has always had a crush on her.
Might get past the no beasty rule if done like this