Contract

In the law of contracts you learn that the offeror is the master of his offer. Meaning that he should lay out all the terms needed to be enforced before there can be a binding contract. This law should fall over into relationships. Going into a monogamous relationship is like a contract. Each party should know the terms that are expected to be filled in order for there to be a binding contract(relationship). These terms should be stated in the beginning so that each party knows what they are getting into. If not those terms are null and void and have no place in your monogamous relationship. So if you feel that you need to have specific things full filled in your relationship please state them in the beginning of your offer to relate, if not then there is no binding contract(relationship) and the other party is free to do what they want.