Hitler's father was in his late thirties when he met and became infatuated with a family relative, his own neice, who was sixteen. They married even though it was looked down on by society. This was the relationship Hitler was born into.
Hitler had the city this happened in bombed during the war.
Hitler himself also had an affair with his own neice when he was in his late thirties, as well as other ladies half his age.
Most of the ladies Hitler had relationships with killed themselves, and some of their writings are used as evidence that he was unstable, possessive, and into shit-play.