[ScottnSue]

Yep, you're not the first to do this. My wife's brother and his wife did this their second time out in their new 5th wheel. Had to call a locksmith.
We keep an extra key in a magnetic box hidden outside for such emergency. Also, I never lock the handle anymore. I always lock the deadbolt instead. I guess I instead one of those nice touch pads lock systems instead. Then I wouldn't have to worry about the key.