Bob, I suppose someone must answer your Q, try to ignore the 13 posts above.
-carry an enormous hiking (empty) rucksack and put it on the seat next to yours on the bus, then lie back and look tired and keep your eyes closed
-or you could take a bottle of apple juice along and spill some on the seat next to you, and if someone passes by, shrug your shoulders and look a bit disgusted in a ''it wasn't me'' kind of way
-also, wear water resistant, fawn coloured underpants or always carry a cardigan you can tie around your waist (it can hide so much)
Good luck