Age gap between your son/daughter and their new flame, would this bother you?

Let’s say you have a daughter/son that is between 20–23 years of age, and they introduce to you their new flame. They seem to be like two peas in a pod, very affectionate, finishing each other’s sentences, always smiling and laughing. However, their new flame is between 34–38 years of age. Would you be bothered by it or wish them well? Should you be bothered since they are adults and can choose their own life? Would you include their new flame in family gatherings?