Priest

It's not necessarily that a Catholic priest can't marry, but that they choose not to through a vow of celibacy. When a man chooses the Roman Catholic priesthood, he is choosing a celibate life as well. It his sacrifice. They are called to consecrate themselves with undivided heart to the Lord and to the affairs of the Lord, giving themselves entirely to God and the community. In this sense they are married to the Church and become servants to the faithful. That being said, there are some married Catholic priests. In the Latin(Roman) rite, married priests are converted ministers and pastors primarily from Lutheran and Anglican traditions. In the Eastern rites, such as Byzantine, Melkite, and Maronite, married men can enter the priesthood, but single men are expected to take a vow of celibacy upon ordination.

If you do not tell them to marry, nothing is lost. They would have got their share of married life in seclusion.