I did this with a big suction cup around my mouth when I was a kid. Broke the blood vessels and I looked like Homer Simpson for a few days, which at that time might as well have been the rest of my life :)
I went into the related videos; apparently there's a sizable nerf community with tricked out guns, war games and other weird shit. It's kinda like paintball, but nerdier and a bit more endearing.