Topics similar to or like Open marriage

Form of dyadic relationship in which an individual has only one partner during their lifetime—alternately, only one partner at any one time —as compared to non-monogamy (e.g., polygamy or polyamory). Also applied to the social behavior of some animals, referring to the state of having only one mate at any one time. Wikipedia

Umbrella term for every practice or philosophy of non-dyadic intimate relationship that does not strictly hew to the standards of monogamy, particularly that of having only one person with whom to exchange sex, love, and/or affection. In that sense, "nonmonogamy" may be accurately applied to extramarital sex, group marriage, or polyamory. Wikipedia

Form of non-monogamy, an intimate relationship structure where all members are considered equal partners and agree to restrict sexual activity to only other members of the group. The practices and beliefs underlying polyfidelity have long existed, but in uncodified fashion. Wikipedia

Form of monogamy that exists when two partners agree to be sexually active with only one another. Being in a long-term mutually monogamous relationship reduces the risk of acquiring a sexually transmitted infection (STI). Wikipedia

Intimate relationship that is sexually non-monogamous. Primary emotional and intimate relationship between two partners, who agree to at least the possibility of intimacy with other people. Wikipedia

Sexual relationship, romantic friendship, or passionate attachment between two people where at least one of the two has such a connection with a third person, either in a formal setting like marriage or informally, without the third person's knowledge or agreement. Affair of the heart, may refer to sexual liaisons among unwed or wedded parties, or to various forms of nonmonogamy. Wikipedia