When Dipper had a crush on Bill but he (Bill) didn't know.

Dipper: ok. I can do this. *a pice of paper in his hands that says "Dear Bill, we've know each other for a long time and I've developed feelings for you.
-Dipper"*
Dipper: *puts the note on Bill's car and waits for him to return behind a tree*
Bill: *sees a note on his car*
Bill: OH NO! NOT ANOTHER TRAFFIC FINE!!I DIDN'T DO ANYTHING WRONG THIS TIME!
Bill: *breaks the note and leaves*
Dipper: *facepalm* I can't believe I'm in love with this idiot