How is it ok to go to a non catholic wedding. Where did the church teach this.
I too would ask this question.
The OP is asking advice but we have no info.
Was one of them divorced? NO you could not attend.
Is it before a justice of the peace? NO you could not attend.
Unless the wedding is in a manner whereby the Catholic church would accept
it as legitimate then I think a Catholic could not attend.
Would the Church accept a marriage between two unbaptised people?