I can hear it now--
"Bless us Father for we have sinned"
"Us??"
"Yes, Father, an act of unsanctified coition." "Us???" "Yes, Father, we have just completed our pleasure and felt we should confess the act."
"Us???? Are you bragging or confessing and where did this act take place?"
"Oh, right here in the confessional Father. We felt that we should confess right after we did it and are mortally ashamed of having gotten it off in Holy Mother Church."
"[under his breath] Hmm, I wonder whether that counts as mortal or venal. And do you truly repent of having unsanctified sexual relations?"
"Not really, but we won't do it in the confessional again. The room is quite uncomfortable."
"[Under his breath] Even so, this is a mortal sin. You will have to make a substantial contribution to the Church, endowing a Mass and buying an indulgence."
"Actually, Father, we're atheists."
"Blashpemers!!! Polizei!!!"

The rest you know.