Mr and Mrs are terms that are commonly used to refer to a married couple. However, there are several other synonyms that can be used to refer to a couple in a relationship. Some of these synonyms include 'husband and wife,' 'partners,' 'spouses,' 'lovebirds,' and 'matey.' Depending on the context and tone of the conversation, each synonym may be more appropriate than the others. For example, 'husband and wife' could be used in a formal context, while 'lovebirds' could be used in a more casual or romantic setting. Regardless of which synonym is used, the important thing is to show respect and acknowledge the commitment between the two individuals in a partnership.