I'm on the Underground, travelling home from university. I got a bit of a cold, I'm sniffling quite a bit. It's a long journey home and about half way through I'm thinking, "I really could use a tissue", but instead of doing anything I stayed reading my book and figured I'd keep sniffling. 
 
Then some twat decides to commit suicide that day, on my train line no less, so it's taking 10 minutes between stops instead of 5. I get overground and that's when it happens - I leave sniffling for that bit longer than I should. Fortunately I'm onto this and my hand is up like a shot. I'm thinking about what to do next when I realise the girl sitting next to me is reading my book, she's right there at my shoulder.  
 
I'm out of options, so I just end up wiping myself on my top. She sees all this, gets grossed the fuck out (it was gross) and changes seat. The guy next to me who was too busy on his Blackberry turns in his chair. Quite embarrassing. Everyone should keep tissues handy at all times at this time of year.