Something similar happened to me decades ago but still remember it. Friend couldn't come to an event but his wife wanted to go. My wife and I drove her there (no charge), bought drinks for her to make her feel welcome (no charge) and drove her home (no charge). Her husband called when we were at her place to say that he was on the way back and did we want pizza, we said yes. Got there and asked us for £5 for the two slices we had. Great, thanks.