Why wouldn't it work?

A boy who had been trying to get ahold of a friend on the telephone decided to go to her house.

how come you didn't answer my phone calls?

I've only been home 10 minutes. The car is still warm. Check it!

sure enough, the car was warm.

Your lie won't work this time!! replied the boy

how could he tell she was lying?

she never left home, even though the car was warm.

because he just a bad boy

i see Report It

he said he was in the house.

because she doesn't drive??
Oh wait, because he called her within the 10 minutes???

Because he had been spying and seen her inside her house.

Is this a trick question?? The boy could tell the friend was lying because of the car. A warm engine means she wasn't home and was out riding around, because there's no way to tell how long she'd been home based on a car's engine temperature, Ha Ha, that's a good one.