The devil woman's conniving tactic to (re)insert themselves into a man's life via sexual practice on a bro.
Dubbed flashbang because it is comparable to the disorienting nature of a flashbang grenade. One does not see or think clearly for a temporary amount of time after said flashbanging has resulted upon them.
This is often done by a "Ratchet" Ex-girlfriend who doesn't deserve to be with the said bro and shortly afterwords begins to weasel their way back into a comfortable status quo so they can suck all life from the target and all bros (and bras) of said target.
to flashbang :
"Dude, did you hear what happened with Randy and Galinda?"
"We've talked about this bro. Those two names are never to be mentioned in the same sentence."
The sexual act of 3 guys forcing a female to service them at the same time. While one guy sticks it in her mouth, the other two have her jerk them off into her both of her ear holes. All 3 men finish by ejaculating at the same time so that the female's ability to see and hear are inhibited, much like a flashbang.
Person 1-Did you see Jessica last night? That hoe was stumblin around like a damn drunk. It was like she couldn't see or hear anything, like fuckin Hellen Keller!
After a long session of flirting and playing around when "blue balling" occurs you proceed to walk into the bathrooom and release the massive load of backed up semen into some toilet paper. When the pain has been releived you now proceed to sprint full force back into the room performing a baseball slide into the bed launching the semen covered toilet paper into the whores face.
Tom: Yo man how was that girl last night?
Victor: Bro she blue balledthe shit out of me.
Tom: Haha, did you do anything about it?
Victor: Yea bro I flashbanged the shit out of that whore and her slutty roomate.
Tom: Damn, I was wondering what that flash was next door.
Victor: Yea that bitch got it good, UAV ONLINE.