One of the odd people who you catch gazing intently at your crotch, also known as a Crotch Watcher, sometimes hot women do this, which is acceptable, however sometimes you catch an old man staring at your package on the bus, that isn't cool
TOM: Dude, look at that Shaft Watcher.
ERIC: WTF are you on about?
TOM: Go on urban dictionary you noob
ERIC: Oh I get it now, lets toe him in.