2.The act of having anal sex with a girl after someone else has done her in the same place.
3.Verb; acting douchtacular.
"Come'on stop douching and find a real man."
"Are you douching again??"
A) To lift up your shirt and show off your stomach while flexing your other free arm no matter what everyone else is doing around you*
* The duck face is not necessary, but is optional. This is only if you wish to be an extreme douche bag.
Tim: Oh he's just Douching, it's one of those new fads. Its kind of like planking but way more stupid.
John: Oh I get it! He's basically acting like the Situation off the Jersey Shore?
Tim: Pretty much....