Angry Vindu

Vindu and his brand new bride were riding home from the chapel in a wagon pulled by a team of horses, when the older horse stumbled.
Vindu said, "That's once."
A little further along, the poor old horse stumbled again. Vindu said, "That's twice."
After a little while the poor old horse stumbled again. Vindu didn't say anything, but reached under the seat, pulled out a shotgun and shot the horse.
His brand new bride scolded him, "That was an awful thing to do!"
Vindu said, "That's once."