Early Christianity had indifference bordering on disdain for marriage, and there's no record of a Christian rite for marriage until the 9th century. Celibacy was considered the ideal. Same for the Shakers, which is why they died out.
If you read his letters in chronological order (not bible order) you can see the wind come out those sails. :)
[0] https://www.catholic.com/tract/the-permanence-of-matrimony
That being said, marriage is still the only appropriate place for sex, and then only heterosexual sex, by church teaching. So both you and the one you replied to are correct.