There's something almost playful, innocuous about watching two grown men in a slap fight with helmets on. Just two giant dudes—who are constantly hammering each other in arguably one of the world's most dangerous sports—patting each other upside a 1.5-inch thick helmet.Well, Steelers wide receiver Antonio Brown and Bengals cornerback Dre Kirkpatrick certainly put on a display of slappy tomfoolery, when a route turned into a slap-happy scuffle between the two players. The ref even takes a kind of funny position on it, letting them go at it for a bit—almost like a hockey ref—before coming in to break it up and throw a flag.Not condonable in the long run, given the number of head injuries players have to worry about already. But seeing as how they walked away fairly unscathed, let's just chalk this one up to silly for the time being.