Is it correct that within an interfaith marriage the non Catholic may still choose to use birth control? What i read said the Catholic has the option of refusing to have intercourse or making very clear that they are not happy with their spouse’s choice, but acknowledging that the consequences are on them and continueing to have relations.
Just wanting to get my facts straight.
When you say the non-Catholic may still choose to use birth control, what do you mean, exactly? I’ll lay out two examples to help be sure some likely confusions are avoided.

Let’s say you are the man, and Catholic. The wife is some other religion. The wife says she wants relations with you wearing a condom as the birth control. You, the Catholic, cannot comply.
Let’s say it is the same man and woman, but the wife goes off and buys the pill and uses it and tells you about it, and you say to yourself, “oh well,” and do nothing, continuing as you always have, or even worse you say “yippee, I’m off the hook”. No, you are not free from culpability here.
The paragraphs you want from the document mentioned above:13. Special difficulties are presented by cases of cooperation in the sin of a spouse who voluntarily renders the unitive act infecund. In the first place, it is necessary to distinguish cooperation in the proper sense, from violence or unjust imposition on the part of one of the spouses, which the other spouse in fact cannot resist.46, 561).] This cooperation can be licit when the three following conditions are jointly met:
*]
*]when the action of the cooperating spouse is not already illicit in itself;47
*] when proportionally grave reasons exist for cooperating in the sin of the other spouse;
*] when one is seeking to help the other spouse to desist from such conduct (patiently, with prayer, charity and dialogue; although not necessarily in that moment, nor on every single occasion).
- Furthermore, it is necessary to carefully evaluate the question of cooperation in evil when recourse is made to means which can have an abortifacient effect.48
Sorry, I’ve tried and tried, and I can’t make the numbering work right on that quote. There are supposed to be three items listed, but it keeps trying to label them with four numbers. Sigh. Computer illiteracy strikes.