Hello, Jean-Marie.You're right, relationship can be well being without married and it doesn't depend on the country. A lot of couples live without being married here too. But...in a civil marriage a lady doesn't have any rights here and I think it's one of the reason to have relationship more oficial.And the other reason that you future wife won't be able to move to your country without a Certificate of marrige because Russia ( and Ukraine aren't members of EU ). Or she can do it illigal and be ready to have problems with the immigration police in your country)))))Good luck and don't be afraid to marry)))