There was very little unusual about my parent's relationship except that he was roman catholic and she was church of ireland. This slightly less uncommon up in the border counties but nonetheless rare - a semi educated guess would put them in a minority of about 1%. That said, my grandparents on my dad's side were also a mixed marriage, and if the day ever comes, so will myself and metalrabbit, my brother and his girlfriend and even though I haven't a clue what the hell my sister is up to these days, it's a fair bet.
Either catholic girls put out easier or it's a matter of the church of ireland populace in cavan being a shallow gene pool.
There lived beside us, not more than a hundred yards or so, a catholic priest of the old skool variety (as they pretty much all were back in 1976). My folks are not exactly traditionalists, I mean they made us go to church every sunday until I was about seventeen but also encouraged us to learn about other faiths (beyond the dean screaming about islam from the pulpits). That said, they decided to get their marriage blessed on both sides of the church so they went to the priest.
He seemed happy enough until it came to the (inevitable) matter of children and didn't so much ask as state that any children would be brought up in the catholic faith.
This didn't sit well for a variety of reasons, one of them being that neither of my folks take well to being told to do anything (ask them nicely and you'll have no trouble, tell them and they'll dig their heels in no matter how silly it might be to do so.... so THAT'S where I get it from...). The other reason was that they both felt that, by and large, the catholic faith was not the better of the two, they believed that confirmation was done too early there and looking back I can't help but feel they knew something about the priest that I didn't. To this day there's nothing but rumor and heresay about the guy but suffice it to say he was not a good man to have around children.
So they said no and the priest was not happy, he refused point blank to bless the marriage or let it take place in the chapel (tradition being such that they would wed in the church of ireland cathedral, my mother's church). Gawd bless 'em, they got up, said that if he wanted to be like that then that was fine and then they walked out. They were married and around eleven months later I arrived.
One day, shortly afterwards, my mother had me out in my pushchair (is it unusual to be able to remember actually being in a pushchair?) when she meets the priest - the guy was only just up the road so it was inevitable.
He greeted my mother, not his biggest fan ever and immediately inquired about me. His second question was "I assume you'll be getting him christened in the chapel?"
Again, my mother refused, saying that I was to be christened in the church of ireland.
His response was typically rational and reasonable - "You're an evil woman, he's going to hell"
To this day I wonder what sort of person I would have turned out to be had she folded and what experiences would have made those differences. What it DID teach me was that a person's worthiness is not a matter of position nearly as much as their actions towards you.
Back in the seventies you did not contradict the church, it just didn't happen, certainly not in the countryside. It took a lot of guts for them to do as they did. I should remember that next time I call them.