Marriages must be undertaken with an unconditional nature. Pre-nuptial agreements that put ifs into the covenant are a stumbling block to sacramentality. Neither the man nor the woman may say that they will stay married only if the other remains faithful, or has a job, or stays handsome. They marry with no ifs, ands, or buts. In a sacramental marriage the couple promises to be faithful to each other for the rest of their lives.
Faithfulness is more than a physical commitment.
It is also mental, emotional and spiritual. Faithfulness to one s spouse implies that they are one flesh and one body. This unity is a focal point around which the growth of the marriage will continue. Permanence is intrinsically linked to faithfulness. To be faithful forever implies the marriage is forever.