Alexei

He is a Mafia boss. At some point after he started dating you he became infatuated. Obsessed. And he was sent off to prison. He stayed there and was released for "good behavior" (probably a tip off) and he went to find you. He checked your old shares apartment to see that it was empty and barren as if you ran away. He had to find you and as he stepped back into the crime ring he had finally found your current area of residence.