Inside a train are Soul, Black Star, Tsubaki and Maka
The train goes through a tunnel
A slap is heard
when the train exits the tunnel
Everyone sees Black Star holding one of his cheeks in pain
Maka thinks: Black Star groped Tsubaki, she didn't like it, she slapped him.
Tsubaki thinks: Black Star tried to grope me, missed and groped Maka. She didn't like it and she slapped him
Black Star thinks: Soul groped Maka, she thought I did it and she slapped me.
Soul thinks: Can't wait for the next tunnel to slap Black Star again!