So, I see lots of posts on why Fred and George didn't notice Peter Pettigrew on the Marauder's Map, but why does Snape not see Peter Pettigrew on the left of the map when seeing where Lupin went, while trying to bring him his potion. Snape would definitely recognize his name. Snape would know the wizard who Sirius killed having been so invested in the event.
I get that he truly hates Sirius and wants him dead. I believe he is truly prejudiced against Lupin. But in his effort to be the best undercover agent ever, he just makes no acknowledgment of Peter Pettigrew in the room and what he's doing there or how he might be validating Lupin and Sirius' innocence.
I'd just like to hear other people's thoughts on it.