Coitus Interruptus!!!

According to Latham’s link to this article about this study, condoms are for cowards:

In a perfect world, “If the male partner withdraws before ejaculation every time a couple has vaginal intercourse, about 4% of couples will become pregnant over the course of a year . . . only slightly less effective than male condoms, which have perfect-use failure rates of 2%.”

In the real world, “Couples that attempt to use both methods consistently over the course of the year can expect typical failure rates for coitus interruptus and male condoms to be around 18% and 17% respectively.”

Analyzing the data using my B.A. in Economics, if a couple has sex 100 times, the guy is going to “forget” to put on a condom 15 times and be “apologetically surprised” fourteen. And I don’t have the stats on people that forget condoms then "interruptus the coitus" but I’m guessing the multicollinearity is low. Scientifically speaking, it’s kind of hard to say you forgot when you ejaculate on another person’s stomach.