|Part of the series on|
|A baker's dozen on sex|
There is a spectrum of definitions for an open marriage, but the general understanding is that the partners involved are not only aware of each other's desires but trusting that said activities will not result in jealousy or other problems that will destroy the marriage. Usually there are spoken and unspoken rules that define the boundaries of what is acceptable (e.g., "not in our marital bed", "no sleeping with my sister", etc.), in order to prevent jealousy as well as problems involving other people who might know the couple outside of their sexual activities.
The following examples of the range of experiences in open marriage:
- One or both partners have sex with other people, but keep the details quiet. This type of relationship often happens when one partner feels he or she is not sexually fulfilled, but does not desire ending the marriage. It can also happen when one partner "knows" (wink-wink, nudge nudge) about the other's affairs, but has other (often financial) reasons for staying in the marriage.
- Both partners have sex with other people specifically during times of separation (like business trips or military deployment).
- Both partners enjoy rich sexual activities outside of the marriage, but limit it to one night stands, so no emotions get brought in.
- One partner allows the other to have sex with others because he or she cannot, usually due to physical limitations such as illness or a disliking of sex. Supposedly, John Edwards had this sort of agreement while his wife was terminally ill.
- It is also alleged that Newt Gingrich asked his first wife for such an agreement.
- Polyamory, where extramarital sexual partners are integrated into family life.
- Polygamy is technically an open marriage, but in practice the women are not usually active with anyone other than a husband.
- Swinging, which has its own gigantic spectrum of practices, involving both partners (either participatory or simply watching).
Dan Savage has argued that relationships are better off when you stop trying to limit or control your partner's sexuality and sexual needs, but embrace it. The idea is that "love" is love, and sex is sex—they are separate experiences. He would argue that one partner will likely not fulfill every sexual need of any individual human, and when we get over the idea that a sexual affair is a bad thing, we will be more open in our lives and happier. He offers the number of men and women who have illicit affairs as a compelling reason to be open rather than judgmental and jealous.
More traditional types would suggest these types of relationships can be healthy in theory but difficult in practice. Aside from jealousy, not letting sexual partners grow too attached or having said activities interfere with family life or the raising of children can cause difficulties if not outright problems.
Technically, from a legal or religious perspective, participants in an open marriage are engaging in adultery.
 Not an open marriage
- Bigamy, which involves one partner having multiple relationships without his or her partners knowing.
- Infidelity, or "cheating" on a partner who did not agree to have an open relationship.