I remember very well the day I met Olimar. It was on vacation with Father at the beach. I was 16. His spaceship, as he called it, was floating in the water. It was damaged and Olimar couldn't get home.
I made a promise to him that day. I was going to marry him when I turned 18. Then he could live in our world in safety. Besides, I had to get married when I turned 18 and I couldn't find anyone I liked. Thus I might as well marry Olimar.
Father was furious. He told me I couldn't marry a being from the stars. That our size difference would complicate reproduction. Olimar himself seemed against our union. I learned much later that he was already married.
Nevertheless, on my 18th birthday, I found Olimar. He had come to terms with the fact that he would have to live in our world for the rest of his life. I asked him if he would marry me. Olimar accepted without hesitation. Nobody wanted him.
Knowing that Father would prevent our union, I ran away from home. I never saw Father again. I, Maria Lindburg, take for my husband Olimar of Hocotate until death do us part.
Olimar can breathe without problems on the planet where Maria lives despite the presence of oxygen. This deviates from Canon, I know, but it makes the story plausible.