Anyway. When I was an undergrad at UNC-Greensboro, I had a flatmate who I'll call P. (at her request), who was raised by her grandmother. P.'s grandmother was by all accounts a good guardian but was also Catholic in a rather traditional way. P.'s health insurance was of course through her grandmother, so P. couldn't get any kind of hormonal birth control without her grandmother's consent. Somewhere along the line, P. had also picked up the idea that condoms weren't very effective even when you used them correctly. She had a long-term boyfriend and didn't particularly want to be a virgin but was very scared of getting pregnant.
Around that time, P. was diagnosed with ovarian cysts and was given a prescription for birth control pills. However, P.'s grandmother insists they call them "hormonal therapy" and that she keep the pills in an old standard prescription-pill bottle rather than the distinctive birth control container. Rather than feeling like she was sick, P. treated this diagnosis as great news: she now had the green light to have sex safely. Her grandmother eventually found out, but relying on something her priest had told her decades earlier during the Vietnam War was actually okay with it. I'm talking about the principle of double-effect; essentially, if you predict an action will have two consequences and you're only doing it because of the first result, the second consequence doesn't really count against you. (This is the theory that lets you drop a bomb on a terrorist, even though you know the schoolchildren who are also inside will likely be killed.)
Something about this amused me to no end. Not the sex per se; at that point in time I believed that pretty much all sex outside of marriage was immoral. (I was a bit prudish at the time.) But the mental contortions both P. and her grandmother went through over all this. Ah, theology!
(For the record, both P., her boyfriend, and her grandmother are perfectly nice people. The first two ended up getting married, as it happens, but not until after college and pregnancy had nothing to do with that decision. They are expecting their first child in August, though. Thanks to her for letting me share this story, and I wish them all the happiness in the world.)