Thanks for reading and commenting. The Catholic response involves vocational priorities.

Catholics choose between one of two service-oriented sacraments helping them determine their top vocation and calling. Holy Orders (becoming a priest or deacon) is a distinct calling to serve the whole Church. Matrimony is a vow to build and give your life to one family: a spouse and children.

Let's start with the Eastern Orthodox Catholic Churches that broke away from Rome (and the pope) in 1054. Orthodox Catholics allow married men to become priests, but they don't allow priests to marry. Similarly, Roman Catholics allow (and encourage) married men to become deacons (a role that is similar to a priest in many ways). Still, once you're a deacon, you can't marry again (even if your wife dies) because being a priest or a deacon is considered an overriding vocation, your top priority.

In both cases, it's about your vocational priority. If you're a priest, you're supposed to put every member of your parish first as your top priority because being a priest is your vocation (the Sacrament of Holy Orders) Similarly, the Sacrament of Matrimony is a vocation: you are called to put your spouse first above all others, and that's why sex is supposed to be reserved for marriage. So when you have a married priest (there are some), they immediately have the great dilemma of who to put first, every single parishioner in need (the calling of the priesthood) or your spouse and your own children.