That is really the very official line of the Vatican Roman Catholic Church.
Any libidinous touch outside of marriage and with someone not your legitimately and religiously married spouse – for Catholics, in the Catholic Church, at that – is a sin, a mortal one.
A digression, a mortal sin will land you in hell if you die without repenting; there you will scream and gnash your teeth for the sheer agony of burning from fire; now for those without teeth, God will provide.
If you are a postgraduate Catholic couple, and both of you are curious and find it practical and effective on the one hand getting some pleasure from sex
and on the other preventing an uninvited pregnancy, then you should consider very seriously and solemnly in favor of anal sex.
Of course, give special careful details to hygiene, sanitation, and aesthetics, though.
That is what I mean by being postgraduate Catholics, I mean that responsibility and liberty, not the anal sex, of course.
But you make the decision, not someone for you.
I just tell you about being postgraduate Catholicism.
What about God, will He be mad for your anal sex?
The pope maybe, but not God; He’s transcendental, beyong all that.
Just don’t hurt your partner and yourself in your sex sports.
God bless you, and remember:
"Primum non nocere,
Ultimum non nocere,
Et interim numquam nocere."
Susma Rio Sep