In his dissenting judgment Mr Justice Nial Fennelly said it was important to identify the "radically different legal and constitutional positions" of the man and the child's mother.
The mother's female partner was "outside those considerations" as she had only such rights as arose from the mother's interest in her child.
The mother had natural and constitutional rights from her relationship with the child, in contrast with the man who was not the father of the child by virtue of membership of a family based on marriage to the mother and had no constitutional relationship with the child. His status was "very different from that of an unmarried father" who had an established relationship with the mother.
The mother's proposal to go to her home country with her child for a year was "a normal and reasonable thing to do" and she had at least the right to choose to do it.
There was an issue whether the man had any right to question that decision and he had produced no evidence to show the child's welfare would be compromised by going abroad for a year.
The court should also attach importance to the agreement between the sides which stated the man "is a friend and has agreed to act as a sperm donor" and "agrees that the child's parents are X and Y [ names of the couple]".
That agreement was difficult to reconcile with the notion of the man becoming a guardian of the child.
The man had claimed the agreement should be declared void as contrary to public policy.
While that was for the High Court to determine, the agreement could not at this stage be assumed to be invalid.
It might well be that consideration may be given at a later time to recognition of non-marital relationships of a kind which have become normal over recent decades, the judge added.