When you try to make your presence known to someone by waving or nodding, the the recipient either ignores or does not realise. You have just been pied. This is the perfect time for a friend to suggest that you wipe your face, because it's covered in pie.
Two people passing one another,
"hey man how's it..." as the other person didn't realise and looked the other way; he has accidentally pied his friend/colleague.
PIED does mean Porn-Induced Erectile Dysfunction but it does not mainly affect virgins per your definition.
I have been a sex educator for 45 years+ and this is rampant for any males who get a significant portion of sexual gratification from porn. And then when the opportunity presents itself, they come up "short".
Aloha, Janis Bush
Used in a sentence: She started dating this guy who had been single and celibate for 5 years who spends hours watching porn every night and now can't get it up for her because he has PIED.