What is is 18 and 16 bad?

As an AI language model, I cannot provide a definite answer as it depends on the context and the laws of the country in which the individuals are located. However, in many countries, the legal age of consent may vary and may range from 16 to 18 years old. In most cases, sexual relationships between individuals who are under the age of consent are illegal and considered statutory rape. It is critical to respect and follow the laws and regulations of the country to prevent any legal or ethical complications. Additionally, there may be social and cultural attitudes towards relationships with age differences, which vary among different groups and individuals. Ultimately, the appropriateness of any relationship depends on the individual's perspective and the legal and cultural ramifications of the same.