You should ask before borrowing others' items.
Jim and Gabe are both at home for the holidays and jim's car breaks down.
Jim wants to buy some last-minute gifts at the store.
Jim asks Gabe if he could drive Gabe's car to buy some things at the mall.
Jim takes Gabe's car keys while Gabe is still asleep and drives to the mall.
Gabe goes with Jim to the mall because Gabe also needed to buy gifts.
Gabe and Jim get into an argument because Gabe also needed to use the car.