Marriage: Is it obligation?

People can marry with someone just because of living with someone else or sharing his or her house. They don't have to love each other. Therefore, it can't  be said that marriage has to include love among members of it. It is just a legal coupling between  man and woman or between same sex people. After a marriage, these couples can  be like juridical person. It means they should make decisions together. Like in business corporations, people must choose the most proper candidates as husband or wife.