Working During Vacation

One customer is doing upgrade this weekend. And they have been encountering problem so far. So we need people to be on call this weekend. And I am one of them. Though it suck to work on weekend but I didn't plan much this weekend anyway. It is either me or another friend. And since he will be moving next weekend, I am sure he would want to pack. Funny thing is we need soooo many people to stand by in case of problem. We need some senior developers who would possibly know more about different area of the code. We need two people to prepare the hotfix. So this weekend we have 5 people on call from the development side, not counting QA. When I was in my old team, it is either me or my friend stay on call. Only one of us is enough to fix the problem, prepare the hotfix, and do the build. It felt such a waste of resource nowaday. As for QA, it is once again my friend being the sucker to be on call. It is especially bad for him because it is his birthday this weekend. He wasn't happy at all. I asked him if I called him to work on his birthday, does it mean I can't be bitter about him calling me back on Christmas few years ago anymore? There was one Christmas he was testing something that I did and he found something wrong. So I end up working during my Christmas vacation. And I still remind him from time to time that he ruined my vacation. I came to a conclusion that as long as it is not me calling him this weekend, I could still stay bitter at him as long as I want.