It depends on a number of factors, including the maturity of the individuals involved and the nature of their relationship. However, it is generally accepted that teenagers should not be involved in serious relationships until they are at least 16 years old. This is because they are still in the process of discovering who they are and what they want in life, and are not yet ready to make a commitment to another person. Additionally, teenagers are often not emotionally or financially stable enough to handle the challenges of a adult relationship.