I don't know about this... either sex in lawful marriage is a good thing, designed by God, or it's evil and we shouldn't do it. Puritans and other heretics said that sex and the whole human body was evil. What is the difference between their heresy and this thinking?
Catholics don't fast from food because it's evil, but because it's good. Similarly with marriage relations.
It's easy to "sacrifice" an evil, but real sacrifices are of what is good.