The constant, unblinking, stare of the "one-eyed monster" (penis) when it is standing at attention (erect).
In my previous life as a nudist, I would pass girls, and give them the ole "pubic stare" inspection - much like a dog sniffs another dog's ass. A man must be free!
The act of staring at a womans ass intentionally.
Maria was blushing as Lucas tried to sneek a pubic stare.