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It is odd that neither the Church nor modern public opinion condemns petting, provided it stops short at a certain point. At what point sin begins is a matter as to which casuists differ. One eminently orthodox Catholic divine laid it down that a confessor may fondle a nun's breasts, provided he does it without evil intent. But I doubt whether modern authorities would agree with him on this point.

Bertrand Russell (2009). “Unpopular Essays”, p.77, Routledge
It is odd that neither the Church nor modern public opinion condemns petting, provided it stops short at a certain point. At what point sin begins is a matter as to which casuists differ. One eminently orthodox Catholic