How did the weasley twins have the marauder's Map for so long & never question why ron was sleeping with a man named Peter every night?

Haha, that's a really good question, now that u mentioned it. Here's the answer to ur question that i found on: link.

■Fred and George Weasley had the Marauder's Map before Harry did, so if Harry can see Peter Pettigrew in the map, then Fred and George seemingly ought to have noticed that Pettigrew was sleeping with Ron every night. They did, however, tell Harry that they found the map in their first year, and no longer need it as they "know it by heart", so it is possible that they have not used it since Ron (and Scabbers) arrived at Hogwarts, or that they believed that the map made a mistake, that conclusion having been drawn by Harry. It is also entirely possible that the twins simply had no interest in using the map to look at their brother sleeping.

this is the answer i found on the official HP wiki :)

That is a very good question.

Oh mrcullen don't be ignorant.
Peter was NEVER famous before harry knew anything about him. So it's impossible for those two to know who he was. Why would they care with so many students around.
Are you sure you read the book?
And I don't think peter sleep in ron's bed. He was a rat, he might put scabber in otherplace specifically for rat/pet.
Is this clear enough?
Quite an Interesting question ;)

Excellent question lol. No idea

Good question lol. I'd say it was either a simple mistake or maybe Fred and George didn't pay attention to that.

1: Ron had only been there for three years. By the time he got to school the Twins would no longer have needed it so they gave it to someone who did. Plus, Why would they pay attention to that area of the school?

I wish I still have that GIF that said
"we love you no matter what baby bro" followed by george winking and laughing.
as reaction to this question.

Maybe they didn't want to be stalker brothers

I have heard one theory that I like. Peter saw the twins with the map and fixed so he showed up as scabbers but when lupin uses t it cancelled out what peter did that is the best theory I have heard