Also the Cahtolic party should get a dispensation form his bishop.
CIC (Latin canon law)
Canon 1108
§1. Only those marriages are valid which are contracted before the local ordinary, pastor, or a priest or deacon delegated by either of them, who assist, and before two witnesses according to the rules expressed in the following canons and without prejudice to the exceptions mentioned in cann.144, 1112, §1, 1116, and 1127, §§1-2.
§2. The person who assists at a marriage is understood to be only that person who is present, asks for the manifestation of the consent of the contracting parties, and receives it in the name of the Church.
Canon 1127 §1. The prescripts of can. 1108 are to be observed for the form to be used in a mixed marriage.
Nevertheless, if a Catholic party contracts marriage with a non-Catholic party of an Eastern rite, the canonical form of the celebration must be observed for liceity only; for validity, however, the presence of a sacred minister is required and the other requirements of law are to be observed.
§2. If grave difficulties hinder the observance of canonical form, the local ordinary of the Catholic party has the right of dispensing from the form in individual cases, after having consulted the ordinary of the place in which the marriage is celebrated and with some public form of celebration for validity. It is for the conference of bishops to establish norms by which the aforementioned dispensation is to be granted in a uniform manner.
§3. It is forbidden to have another religious celebration of the same marriage to give or renew matrimonial consent before or after the canonical celebration according to the norm of §1. Likewise, there is not to be a religious celebration in which the Catholic who is assisting and a non-Catholic minister together, using their own rites, ask for the consent of the parties.
CCEO (eastern canon law)
Canon 828
§1. Only those marriages are valid which are celebrated with a sacred rite, in the presence of the local hierarch, local pastor, or a priest who has been given the faculty of blessing the marriage by either of them, and at least two witnesses, according, however to the prescriptions of the following canons, with due regard for the exceptions mentioned in cann. 832 and 834, 2.
§2. That rite which is considered a sacred rite is the intervention a priest assisting and blessing.
Canon 834
§1. The form for the celebration of marriage prescribed by law is to be observed if at least one of the parties celebrating the marriage was baptized in the Catholic Church or was received into it.
§2. If, however, a Catholic party enrolled in some Eastern Church celebrates a marriage with one who belongs to an Eastern non-Catholic Church, the form for the celebration of marriage prescribed by law is to be observed only for liceity; for validity, however, the blessing of a priest is required, while observing the other requirements of law.
Canon 835
Dispensation from the form for the celebration of marriage required by law is reserved to the Apostolic See or the patriarch, who will not grant it except for a most grave reason.
Canon 839
Before or after the canonical celebration of marriage, it is forbidden to have another religious celebration of the same marriage to furnish or renew consent; likewise, a religious celebration is forbidden in which both the Catholic priest and non-Catholic minister ask for the consent of the parties.
