I’m not entirely sure about the mythology of the Harry Potter Universe, and I’m sure you die hard fans could possibly debunk this theory, but here’s the set up to the meme. The Marauder’s Map can show the name of pretty much anyone in Hogwarts castle, regardless if they’re animagus or human. So the idea of Peter Pettigrew showing up on the map was a pretty big deal when the map came into the hands of Harry. We know now that Peter Pettigrew was Ron’s rat all along. But the real questions is that for years, George and Fred have held the map in their hands and used it to navigate the castle. Surely they saw the following: their brother Ron and a mysterious man named Peter Pettigrew together nearly all the time on the map, especially at night. Sure the Maruader’s Map doesn’t explicitly tell what two people are doing, but surely one can insinuate something that happens nearly all the time.
Another hole in Rowling’s universe? Or quite possibly a disgusting truth to the two twins. HP still blowing my mind after it’s techincally over.
Banana Scoop 
What On Life and Stuff said…. i’ve never thought about that either.
Wow… hadn’t thought about it, but you’re absolutely right!!