What is Hex Message?
1.
A nasty, malicious and/or subtly unnerving text sent from someone (usually a current or ex-girlfriend) designed to get inside the recipient's head and ruin their day/night.
A good example would be 'Your roomate says Hi' from a recently broke up with ex girlfriend right as the former boyfriend is entering his favorite bar for the evening.
"yeah dude let's fuckin' party!"
*phone beeps, looks at phone, goes sheet white, swallows hard and puts the phone back in pocket*
"oh man looks like the ex-gf just hit him with the hex message, he's worthless for the night"
See
