These are "The Try Guys"; a group of guys who (you guessed it) try things.
In a recent upload, they wanted to experience what it was like to have boobs for a day. And, if you're a girl, you know they'll feel pain, if you're a guy (and don't have boobs) you'll soon realize why sometimes women don't like their boobs. It kinda opened my eyes to a different point of view I've never thought of.
Oh, and VIEWER DISCRETION IS ADVISED! The "Try Guys" cuss a lot plus if talking about boobs makes you uncomfortable you shouldn't be here!