Why is wrong have sex with kids?
Why is wrong have sex with deaths?
Why is wrong have sex with animals?
Why the Catholic Church (and the Christians) says "don't use condoms", "don't have sex before marriage", "live your marriage (conjugal life) with just your husband/wife" and so others things?
The priests don't know anything about sex and sexual pleasure. But they know God and they talk to God, like me.
I have my girlfriend and we are very happy without have sex before our marriage. We know God together and He wants our chastity.
If the Church and the Christians say "don't have love relationship with anyone of the same sex" then it's the desire of God.
Why doesn't God want the homosexuality?
God wants our happiness and our happiness is not pleasure.
We can have the true happiness just in the God's desires.
God created the man and the woman and He said (Genesis 1, 28):
Be masters of the fish of the sea,
the birds of heaven and all the living creatures that move on earth."
If we don't do what God said then we will have problems, because He created everything and He knows everything and everybody. If God said for us be fruitful and multiply, then we have to do it.
But you say "the priests don't have families".
The priests don't have marriage because God wants them for Him, us and the Church. They can't have a own family because they will have many people for care and save.