Longer stay in Vietnam with visa exemption

Longer stay in Vietnam?
Hello, i have been many times in Vietnam for business and private reasons. 2 years ago I met a girl and since last year we are engaged. I am not sure when will we marry, but for the moment i am thinking to buy a small house. the house will be on my fiance’s name. i am old enough, i know what i am doing and taking a risk by my free will. however, a question is: is there any way to stay, say, 6 months or longer for private reasons (tourist visa?) or there is only 3 months visa? If I have 3 months visa does it mean i can stay in Vietnam for 3 months? also (this is not your field, but just asking), in your experience, is there any problem we stay in the same apartment since we are not married? i heard some stories that police made problems for that and many other where there were no problems at all.

Answer about longer stay in Vietnam
Dear BurbankNice to hear that you decide to reside in Vietnam. Sure, you have 2 options below to get your long-term Visas in Vietnam:
1 – You apply for a 3 month multiple entry visa – either through our online service or through Vietnamese Embassy in US. When you are in Vietnam, you can extend your exisiting visa for further 3 months.
2 – If you marry a Vietnamese girl, you are eligible to apply for a 5-year visa exemption through the Government website below: http://mienthithucvk.mofa.gov.vn/
We hope that helps.