My mom says "na mij de zondvloed", and Dutch has a tendency to loan from French (invasions and all that), and "après" is after iirc and "deluge" means a lot of rain in English right? So I guess it means what my mom says: "after me, the huge flood", or whatever that biblical story's rain/flood was called, the one where Noah got a ship with every type of animal to eat^W, ahem, rescue
More loosely translated: I don't care what comes after me
I'm sure GP's next of kin will be very pleased with them... but yeah it's the mode most people operate in. Short term gains, long term scorched earth
(My mom doesn't mean that seriously, more of a saying she uses in specific cases like about what happens to the house. Basically saying she doesn't care about a particular physical property or so.)