See Catechism 1579 and Catechism 1599.
In fact, it is also explicitly stated when Holy Orders are conferred:
You ought anxiously to consider again and again what sort of a burden this is which you are taking upon you of your own accord. Up to this you are free. You may still, if you choose, turn to the aims and desires of the world (licet vobis pro artitrio ad caecularia vota transire). But if you receive this order (of the subdiaconate) it will no longer be lawful to turn back from your purpose. You will be required to continue in the service of God, and with His assistance to observe chastity and to be bound for ever in the ministrations of the Altar, to serve who is to reign.
Celibacy is what a priest is expected to practice, married or not.
I do not point this out to discredit Roman Catholicism as a "false Christianity" or to denigrate faith! On the contrary, I believe that only by acknowledging the failures and shortcomings of our own institutions will we fully understand the power and infallibility of the Word of God.
ANY organization headed by man - even if set up by God - will fail; one needs to look no further than the lesson of the golden calf! God Himself appointed Moses and Aaron as the leaders of the tribe of Israel, and God Himself dictated how to worship Him. Yet even Aaron failed - even while Moses was on Mount Sinai meeting face-to-face with God!
NO institution is infallible or pure; our only trust is in the Lord. Rules, laws, disciplines, catechisms of man will not save us. ALL have sinned and fall short of the glory of God! Only by believing on Jesus shall we avoid eternal death.
My church, my pastor, myself - we are all fallen, we all fail. The only way to correct is with daily prayer and meditation on the Word of God. That is the only thing we have that Jesus has claimed as infallible and inerrant. Recognizing the shortcomings of our own churches will drive us back to the Word, where we are supposed to be.
Where's your documentation of this:
Celibacy is what a priest is expected to practice, married or not.
Furthermore, celibacy is and remains a voluntary vow.
The teachings of the Catholic Church are protected from error by the Holy Spirit. They are without error.