Objection 1. It would seem that even after the marriage has been consummated one consort can enter religion without the other's consent. For the Divine law ought to be more favorable to spiritual things than human law. Now human law has allowed this. Therefore much more should the Divine law permit it.
Objection 2. Further, the lesser good does not hinder the greater. But the married state is a lesser good than the religious state, according to 1 Corinthians 7:38. Therefore marriage ought not to hinder a man from being able to enter religion.
Objection 3. Further, in every form of religious life there is a kind of spiritual marriage. Now it is lawful to pass from a less strict religious order to one that is stricter. Therefore it is also allowable to pass from a less strict--namely a carnal--marriage to a stricter marriage, namely that of the religious life, even without the wife's consent.
On the contrary, Married persons are forbidden (1 Corinthians 7:5) to abstain from the use of marriage even for a time without one another's consent, in order to have time for prayer.
Further, no one can lawfully do that which is prejudicial to another without the latter's consent. Now the religious vow taken by one consort is prejudicial to the other, since the one has power over the other's body. Therefore one of them cannot take a religious vow without the other's consent.
I answer that, No one can make an offering to God of what belongs to another. Wherefore since by a consummated marriage the husband's body already belongs to his wife, he cannot by a vow of continence offer it to God without her consent.
Reply to Objection 1. Human law considers marriage merely as fulfilling an office of nature: whereas the Divine law considers it as a sacrament, by reason of which it is altogether indissoluble. Hence the comparison fails.
Reply to Objection 2. It is not unreasonable that a greater good be hindered by a lesser which is contrary to it, just as good is hindered by evil.
Reply to Objection 3. In every form of religious life marriage is contracted with one person, namely Christ; to Whom, however, a person contracts more obligations in one religious order than in another. But in carnal marriage and religious marriage the contract is not with the same person: wherefore that comparison fails.
Source: Summa Theologica (New Advent)