I saw this a couple of days ago, and I really didn't think much of it. Kind of staged? Maybe.
But if it's real, I don't think it's that funny of a bit -- And I've got a heck of a sense of humor. Is there ever a situation where, as a joke, you want your loved one to earnestly believe you are dead? Noooooooooo. And did anyone in that group ever think to say, "Hey, hoss. It's a marriage proposal, not America's Funniest Home Videos"?
P.S. Check out her "no way" at around the :35 second mark. Sheesh. Now that would make me want to jump off the building.