Heading down to France, there was this bad smell and no-one knew what it was until we got to a service station that this guy walked rather oddly off the bus - leaving a big brown stain on the seat...
People had to sit next to that for the rest of the journey.
We teased him about it until eventually he left the school after GCSE, and went to a college. Sadly for him, someone else from the school went there as well and kept on teasing him.
We still mentioned it most weeks until the end of 6th form.