My friend had to take his car to the dealership, & it had to stay there over the weekend. They did not have a loaner car for him, so I allowed him to use my car for the weekend because I was going to be out of town anyway. When he returned the car to me, it was at a half-tank of gas. Isn't it common courtesy to fill up someone's car to a full tank when you borrow it? I did not say anything to him about it. I just grinned at him when je returned the car, secretly seething about the her audacity to not fill up the tank. I have been talking sh!t about him to our friend group for doing that, and they have run back and told him. When we went out last night, he ain't even give me a glance. The group is split. Some say that he is wrong, but others are saying that I gave him the car at a 1/4 a tank and that he filled it up already when he had it. Am I tripping about the gas situation?