If this method is used several times, don't use it, or it can be used as an excuse to accompany your parents. You can say that you haven't eaten with your parents for a long time, and at this moment, the company promised to accompany your parents to eat on their holiday day. I believe that for this reason, they will not disturb your time with your family, which is a good way.
If these methods are not feasible for you, you can also use yourself as an excuse for being unwell during this time. Make up a pathology at random, and then make up a story that the doctor told you not to drink, not to stay up late, and pay attention to rest. This is a very simple and common method. Even if people doubt whether it is credible, they won't really let you go hard. After all, I am not a particularly good classmate, so there is no need to put down my face and make excuses.
In addition to these reasons, there are many reasons, such as busy work and overtime. You can tell him that you are preparing a project recently, and you have been so busy that you don't even have time to eat, even if you want to go. Then I verbally promised to get together again next time, expressing my regret that I couldn't go first. As for when the next time is, I will tell you. Anyway, there are so many reasons, just make up another one. I believe that such boring parties are rejected a lot, and they should know it in their hearts.