Why bring this up when you probably will not marry a Vietnamese person?
Well you too can seek a deeper connection to a country by spending some time before you go developing your own personal connection to the people and culture.
The Vietnamese, like many in the world are eager to learn English to advance in business and their professional careers. Some start learning English quite early but lack a native speaker to practice with to improve. That is were you come in; there is many Vietnamese that are online to connect with English speakers to improve their skills. You can explore some aspects of Vietnamese life and what is something that would be interesting to do when you come to Vietnam. This of course is a longer term commitment than hiring a guide but it can become a friendship you can enjoy for years to come.
Where do you find these eager learners? well I can not endorse any site or service but try a google search Vietnamese seeking English practice and give it a try.
I have learnt much from my wife about the beauty of Vietnam and even more via her connections in all regions of the country. It brings a richness to travel that no guidebook can match. You also can learn what to be wary of while you make your way through the country and to understand the rational to some of the things you see here.
You may not make a lifetime friend eager too show you around the country but you can make friend that will be a resource when you finally do come to Vietnam. At least you may learn more than another cat video on youtube can show you :).
You can skim through countries with tours that show you the tourist traps or you can spend some time reaching a greater understanding of the people and place that is Vietnam.