Nope. We’d have the exact same conversation.
Disagreement, I can live with. Being called upon to bless a blasphemy or a sacrilege, that’s another thing entirely.
No, upon reflection, I will concede, “blasphemy” or “sacrilege” isn’t quite the word. We all misspeak from time to time. But I would still not go witness the
de facto removal, you could say, of one of my descendants from the Catholic Church, and I would not go to celebrate the fact that my grandchild was going to be raised without the fullness of the Catholic Faith in union with the Holy Father. Again, my stated stance would be along of the lines of
“you know I cannot do this, and you know why — if the tables were turned — if you were the faithful Roman Catholic and I had, let’s say, married outside the Church, fathered another child, and were having your half-brother or half-sister baptized by Protestants— I would not expect it of you either”.
Just for the record, if this grandchild of mine were being confirmed as a young adult, I would reluctantly attend the ceremony and give as generous a gift as I could. It would not be their fault that they were raised in error, and it would be their decision. (But I would hope that I could find a way into their heart, mind, and soul to bring them into the one true Church one of these days.)
We could also ask why do Catholic clergy attend Protestant ordinations, and so on, knowing that it is an invalid sacrament? It’s out of respect for the persons, for the in-good-faith intentions of the ceremony, and also out of sensitivity to our relationships with people we disagree with.
If someone had left the Catholic Church and were being ordained a Protestant minister, I wouldn’t attend that either, for the same reasons. If they had never been Catholic, no problem. But I would not celebrate a defection from the Church.
The wife of a friend of mine was ordained as an Episcopal priest (AFAIK she had never been Catholic). While I didn’t attend the ceremony — we weren’t that close and I wouldn’t have been expected to — I always spoke of his wife’s decision and ministry with the highest respect. (Would be nice if the PECUSA weren’t officially pro-choice.)