I gotta laugh at the reactions to my initial comment. There must be a lot of guys out there whose only dating experience is being the winner of a dating sim game where the girls are all submissive and will put up with any abhorrent behavior thrown at them. The reality of the situation is that he had the opportunity to call his girlfriend before he took his friend home, knowing it would take about 30 minutes, but he didn't. Why? Because he is not considerate enough to let her know that he might be home late. It never even occured to him that the thing to do would be to let her know that the party was over and that he would be delayed in returning home because he was taking his friend home. If he was really considerate of her, he would have absolutely refused to take part in the goukon, no matter what. You know damn well that if the shoe was on the other foot, he would have been livid if she went to a goukon without him, and especially if she had come home the next morning.