It's immoral to poke holes in condoms.
Jake is about to have intercourse with Mary who asks him to wear a condom and  hands him one.
Jake wants to put on the condom.
Jake takes the condom and without much ado slips it on before contiuing.
Jake takes the condom and lets his nail scratch a hole into it before slipping it on.
Mary does not get pregnant nor does she get any diseases transmitted to her.
A few weeks later Mary realizes that she is now pregnant with an unplanned child.