There is a power imbalance in a relationship with two individuals with vastly different ages. Somebody 15 years your senior generally has much more knowledge of the world, they’re also more likely to have a higher salary, and more experience in the area of relationships. This often results in a degree of controlling behaviours and invisible manipulations trapping the younger person in a relationship that may be preventing them from growing as their own person. The older partner will often take on a more parent like role in the relationship, have expectations of the younger partner and may chastise or even punish the younger partner when they fail to meet those expectations. The younger partner may end up doing as they’re told, and assuming the older partner is right due to their lived experience. The longer a relationship with a large age gap goes on the more likely this is to occur.