Roughly speaking, marriage means united its two kinds of creatures live or die, be man and man, man and plants, man and robot sex, man with camel, and others. The purpose of marriage itself is to formalize a relationship to be legal according to the norms of religion, rule of law, and social norms.
So it - it makes what you have to get married? Here are some reasons:

No one who does not feel pain after a breakup, especially if we are in party decided lover. For some people, even a breakup can leave deep wounds that are difficult loss and prolonged.