"Maybe she's Catholic. Oral sex (with orgasm), even among married couples, is considered sinful by the Catholic church."
Whatever. I suppose Catholics honor this, one and all. Right.
What does that have to do with anything? Catholic belief isn't defined by what most or all Catholics do, any more than Jewish belief is defined by the fact that most Jews don't keep kosher.
Orthodox Christian believers believe in objective moral truth. Something can be wrong even if 100% of people do it, because (with 2 notable exceptions, as far as Catholics are concerned), every person who's ever lived has sinned.
You evidently don't believe in objective moral truth. Your belief seems inherently self-contradictory and paradoxical, because to deny the existence of objective moral truth is automatically to assert an objective moral truth.
And, yes, my wife and I try to be faithful to the teachings of our Catholic faith in every part of our lives, including in the bedroom. We've found it to be profoundly fulfilling and beautiful.