You shouldn't track sand into the house.
Brad and his wife Cindy have come back from the beach with shoes full of sand, and they're at the front of their home.
Brad wants to enter the house.
Brad opens the door to their home but takes his shoes off and wipes his feet before going in.
Brad opens the door to their home and walks in just as he would normally.
Cindy is delighted to see Brad remembered that his feet are full of sand and didn't bring it into the house.
Cindy gets mad at brad for not paying attention to his feet and bringing tons of sand into their house.