This is how I see marriage

humans
- id
- forename
- surname
- birthdate

binary_marriages
- id
- partner_1_id (foreign key references column humans.id)
- partner_2_id (foreign key references column humans.id)
- marriage_date
- divorce_date (NULL if still married)

This is how I see marriage:

urn:md5:17b3d36785f0ba0f0b8c402211012d8f<sup>[1]

<sub>References　　　　　　　　　　　　　　　
1. http://danbooru.donmai.us/post/show/161856/. Retrieved on 2009-03-04. Masturbated on 2007-11-25, 2007-11-28, 2008-02-29, 2008-06-11, 2008-07-12, 2008-07-12, 2008-12-24, 2009-01-13, 2009-03-04</sub></sup>