Marriage contracts are a mark of civilisation, defining the rights and duties of both spouses as well as the consequences should infidelity occur. Many major religions around the world, including Islam and Judaism, establish a marriage by a contract first, which is fulfilled by sexual relations. Some countries, like the United States, will only honour certain agreements of a marital contract, though in most states the infidelity clause and its agreed-upon consequences are given merit. Wording your contract requires some advice from spiritual mentors as well as an open discussion with your spouse-to-be.
Talk to your religious adviser, such as an imam, rabbi, priest or pastor, for religious marital contract wording and traditions if you belong to an organised faith. Many religions sanction and have traditional marriage contracts that discuss the rights of each spouse, especially regarding infidelity, on which you can base your contract.
Discuss with your partner the limits of your relationship, such as sexual exclusivity. Marriage, by definition, tends to include sexual exclusivity. However, in some religions and countries, polygamy is permitted and in some cases encouraged. Note that you should follow the laws of your country, as polygamy is illegal in some countries, such as the United States.
Take the clauses you agreed with from the religious marriage contract, if applicable, and write them down on a piece of paper. Also write down the limits of the relationship in as clear terms as possible, such as "will be sexually exclusive to each other."
Discuss and decide what the consequences for infidelity shall be. Many prenuptial agreements have legal infidelity clauses: "Should the infidelity of one spouse result in the dissolution of marriage, the wronged spouse shall gain" items such as extra financial support or full ownership of the primary residence. Other marriage contracts lay out non-legal terms in the case of infidelity should the marriage not end: "If either spouse is unfaithful to the other sexually, with kissing, sexual fondling or intercourse of any kind, it grants the wronged spouse the right to" whatever the terms are, such a greater monthly allowance, or requires the spouse who cheated to check in at certain intervals or never attend social engagements without being together. Write down the terms you agree upon as explicitly as possible.
Type "As of" with the starting date of your marriage contract following it, then your full name and your future spouse's full name. Finish the sentence with "agree to the following terms upon their marriage" with a colon.
Type the clauses from any religious text exactly as you agreed upon. Type out the infidelity clause in explicit terms as discussed and agreed upon in Step 4, both the legal ones and the personal ones. Print the contract.
Get the marriage contract notarised, which requires the presence of both signing parties, and file it with your attorney if you have one.