Researchers estimate that up to 6 percent of marriages are considered "open" – that is, partners have an arrangement in which they are not monogamous with their spouses – but is an open marriage an option in your relationship? First of all, the definition of what constitutes an open relationship is highly subjective, depending on the couple. One spouse may feel like one-night stands are OK, while the other spouse may feel extramarital relationships should stop short of sex. Some couples allow extramarital sex in the presence of the other partner, aka "swinging"; some allow sex independent of one another. One thing participants must agree on is the terms of the arrangement. Communication is key when broaching the subject of developing an open relationship, and spouses must be comfortable enough with one another to spell out their own desires and be receptive to the other spouse's desires. The courage to speak up if the arrangement is disagreeable in any way is integral to a successful arrangement. Communication lines need to be more open than in a monogamous relationship, and partners in open relationships should feel free to voice opinions and make changes to the arrangement as needed. This is where the cons of an open marriage start outweighing the pros. Perhaps stepping out on the marriage offers a dynamic that refreshes and reinvigorates the marriage. However, jealousy or competitiveness can arise from new experiences with new partners. The demands on a non-monogamous partner's time when he or she has more than one partner can be stressful as well. The security of a committed spouse and feelings of calm that arise from monogamy are absent in an open marriage and may lead to self-esteem issues. And if kids are in the picture, discretion is of the utmost importance.