I can speak from my own experience, that it is a sin for the Catholic/non-Catholic union if the Catholic does not get a dispensation. However, an important point to make, at least according to the priest performed our third marriage (more on that in a second

), is that the children of such a union are not bastards. They are still considered legitimate children. In fact, the whole question of whether the couple is fornicating or not seems a little moot to me. Being that the marriage is invalid, they are in a constant state of mortal sin - equivalent to a couple “living in sin.”
Now for the story:
May, 1986
Me: Baptized/Confirmed, though non-practicing Presbyterian
Spouse: Cradle Catholic, but not particularly religious.
My mom wanted us to live together first because of our age (20). She is divorced/remarried and is of the false opinion that living together helps. Her mom wanted us to get married - primarily for reasons of limiting scandal. We got married with a JoP - told her mom, but didn’t tell her mom.
September, 1986
Wedding with very small group of close family/friends (~30) on a large hotel balcony with a Presbyterian minister. Only my brother seemed to notice something was odd (“don’t you need to sign a marriage certificate or something?”)…subject was successfully changed.
Easter, 1990
With baby number one on the way, we (wisely) decided that it was best to raise children in a faith that both parents share. While my wife was not particularly religious, she had more of an issue leaving the Catholic Church than I had considering the Catholic Church, so we decided that I would try Catholic parishes first. I liked it - went to RCIA and fell in love with the Church! Our priest said, “you don’t need to get your marriage blessed, the Catholic Church recognizes Presbyterian marriages.”
February, 2000
Baby number three is born, and we go to get her baptized at the parish we previously attended in California (we lived in CO at this point). Somehow the subject of our marriage comes up, and Fr. Nguyen says to spouse “you didn’t get a dispensation?” We say “what’s that?”
September, 2000
Married in the Catholic Church, and, no, we didn’t abstain for seven months.
Fourteen+ years of fornicatin,’ and we didn’t know it! Okay, we knew about some of it…
It bothered us that the priest at the time of my conversion didn’t counsel us properly, but I have forgiven him. As I was discussing with our recently transferred priest last week, I recognize the irony in the fact that this very “orthodox” or “homestyle” (thanks tee) Catholic probably had an easier time converting in that California “cafeteria” Catholic parish.
