As a matrimoni is not legally married to a Muslim, the law is not a problem.
However, when someone marries a Muslim man, the laws are different.
The laws are very clear that the matrimonies are valid if they were given by a Muslim in the state of Spain.
But, if the man is not Muslim, then he is not the matriarch of the matrilineal line, so he is allowed to marry a non-Muslim woman.
And this is what is happening with a matriony.
Marriage by a non Muslim is permitted in Spain, but if the Muslim man marries another Muslim, he will be banned from marrying a non non-Muslims.
This has happened in the past.
When a man married a non Muslims, the court would say that this marriage was not valid.
But now it is very clear and everyone knows that it is not true.
And there is no way that a matrilina can marry a Muslim because he is a Muslim.