The context of the following conversation is Sasha was at home grading papers and drinking coffee. The coffee spilled and Sasha made a mess of their tests.:
Sasha says I felt so bad.  I poured myself a full cup of coffee before grading papers at home in my kitchen, I spilled coffee all over the papers. They are a complete mess..
The friend responds As long as the students get their grades, I don't think they care that much..
Sasha responds I hope not..
The friend responds As a positive, they are used to spilled coffee on their work..
Sasha responds They'll forgive me, I hope..
The friend responds I wouldn't sweat it..