Math Class Prank Gone Wrong

So today in math class, I thought it would be funny to put a note that said 'This test is cancelled' on the board when the teacher left the room for a moment. But turns out, my friend accidentally handed me her actual test instead of mine, and when I grabbed the pen to write the prank message, I ended up scribbling all over it! My heart sank thinking about how mad she must be...but she just laughed and said it made her test look like art now. Still kinda embarrassed though.