Actors do it. Rock stars do it. Even William and Kate do it. What about the rest of us? That is, living together without being married.
When asked for their faith's position on the practice, some religious leaders cringe at the practice, and others are more accepting.
The Southern Baptist Convention does not have a hierarchy that gives official positions, but resolutions are provided on particular topics, said the Rev. Paul Brooks of First Baptist Church of Raytown, Mo.
Resolutions have been passed in support of conventional marriage, and his church strongly supports that, he said.
"We believe that if people are living together, they should be married," Brooks said. "But we welcome everyone. We don't judge them (those who are not married) or make them feel bad. We simply teach the Bible and what we believe to be true.
"Marriage is the foundation stone of any healthy society."
In contrast, the Rev. Lee Devoe, who functions as an interim Unitarian Universalist minister, said: "Whatever structure our relationship takes — marriage or living together, gay or straight couples — we hope that they will be embodiments of love and integrity."
She said the important thing is that people act in a way that affirms the dignity and integrity of others and themselves.
"Isn't it wonderful that we have more options and more ways to be in a relationship and to experience life?" she asked. "At the same time, marriage is a public event. Of all life's passages, traditionally marriage has had the most impact on society."
She said that among the factors to keep in mind are that while living together might ensure the success of a future marriage, the social protections marriage offers aren't there, and not all couples (such as same-sex couples) have the choice to marry.
Buddhism doesn't consider a unmarried couple living together to be immoral, said Lama Chuck Stanford of Rime Buddhist Center in Kansas City.
"The key is avoiding harming others. For that reason, there is emphasis placed upon being faithful to one's partner, married or non-married, gay or straight."
Hindu social customs do not encourage living together without being married, and "it rarely happens," said Arvind Khetia, an active Hindu. "We do not follow the lifestyle of the larger society."
Likewise, living together is not allowed in Islam, said Ahmad Ghosheh, president of the Islamic Society of Greater Kansas City.
"Marriage is the most important part of family life," he said. "Anyone who is of age should get married. Technically, anyone past the age of puberty can get married, but normally it would be 18, 19 or 20."
Even Muslims who are not from religious families know certain things are not proper, so interactions between males and females are strictly observed, whether among very religious or very liberal Muslims, Ghosheh said.
Rabbi Scott White of Congregation Ohev Sholom in Prairie Village, Kan., said Judaism takes a different approach.
"Jewish law would say that when a couple is living together, that in effect that is a consummation of marriage, and it becomes like a common-law marriage, whether the couple realizes it or not," he said.
"So if William and Kate were Jewish, they would be considered married in the context of Jewish law."
In the Catholic Church, couples who want to be married in the church should not live together or engage in premarital sex, said Ken Greene, director of the Family Life Office of the Diocese of Kansas City-St. Joseph, Mo.
"Some tend not to marry in the Catholic Church because of this policy," he said. "Some people take offense to it."
The African Methodist Episcopal Church does not officially condone couples living together without being married, said the Rev. Stacy Evans, pastor of Allen Chapel A.M.E. Church in Kansas City, Kan.
She said some couples in her congregation are not married. Some low-income parents don't get married because they will lose benefits, especially if the father doesn't have family health benefits.