[Natural Law]

"I have read that the priests were not allowed to have sex before they said mass because their hands would touch “christ”"

But I'll bet you can't recall where you read that. I'll also bet it wasn't in any Catholic Encyclical or in the Catechism.

[RnMomof7]

Ya never want to bet with me NL :)

306-Council of Elvira, Spain, decree #43: a priest who sleeps with his wife the night before Mass will lose his job.

[Houghton M.]

The requirement of abstinence before service at the altar goes back to Jewish priestly practice. Priests served at the temple in rotation and were to abstain when “on duty.”

Christianity saw priesthood (bishops, from which office that of priest is derived) as a totally consuming, self-sacrificing office. St. Paul assumes that all devout Christian couples will regularly abstain from marital relations in order to pray and fast. Priests’ whole lives are to be given to what other couples do regularly but intermittently rather than continuously.