Boy Howdy
Just wondering...does this sarcastic putdown derive from the Howdy Doody Show?
I googled your phrase and I did not see it used as a putdown at all. It was used on an assortment of sites as an experssion of amazement as in "Wowee, boy howdy, what great chilli" or "boy howdy, what a great time we had at the Johnson cookout".
I just oogled your google and feel totally bamboozled. I came across it in a reference to a motorized snowboard, something like, "Boy howdy, I can't wait for *THAT* to hit the stores." Definitely sarcasm. Of course, the world is full of people who don't use or recognize sarcasm at all...
It's all in the way you say it.
The sarcastic part of the snowboard statement is the latter part. "Golly gee, I can't wait . . ." would be sarcastic too, even though "golly gee" can be used "straight." What intro, then, is always sarcastic, never straight? Oh, I guess "la-de-da." Maybe "whoop-de-do."