I met my husband in Germany in my hometown. He was stationed not far from there. Although I learned English in school I had forgotten a lot of it, because it was the Oxford English we were taught. So by the time we met I hardly spoke the language. When we dated and after we married, we went to lots of company parties and to movies on the post were he was stationed. Also he made me answer the letters from his mother and sisters. I used the German-English translations first until I didn't need them any more. Also I remember that I translated everything in my head from German into English, or visa verse. After a while I did not need to do that anymore.
By the time we came over in 1966 I was already able to speak, read and write in the English language. Also when my husband and I met I had a little 2 year old boy, (he and my husband shared the same birthday btw. Of course I spoke only German with him at first. Then when our son was born in 1963 I started to speak only English with him. My older son learned eventually to speak English and he has always gone to an American school
One of my church friends met her husband when they both lived in Mexico. She spoke only Spanish, and he spoke only Polish! They went out on dates along with their boss, who spoke both languages.