Someone who stares at your meat while using the urinal next to you.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

one who looks at the male genitalia.

to watch or stare at male body parts, particularly the genital area.

The act of looking at a mans package. Staring at a mans penis.

to check out (hot) dudes.

woman starring at a guys package through his clothing.