Condoms have a better safety rate than that"”in the 80-90% range"”when used properly. (Please note that 90% is WAY less than 100% when we're talking about birth control, because, when you get pregnant, you get 100% pregnant...and the same goes for AIDS, herpes, chlamydia, and other STDs.) When condoms fail, it is usually for one of the following reasons: 1. The condom was not put on properly. If you don't leave a reservoir at the tip, there's not enough room for the condom to hold the ejaculate. This can cause the condom to rupture. Some condoms have a reservoir tip as part of the design, but if yours doesn't, be sure to pinch the tip when putting it on so as to create one. Excessive stretching of the condom can also weaken the latex (or polyurethane; we hope you're not using lambskin in 2002), making the condom more prone to breakage. Unless you're John Holmes, you don't need to pre-stretch your condoms. (If you are porn star material"”and don't flatter yourself"”buy extra-large condoms, rather than stretching standard-issue rubbers.) 2. The condom was put on too late. Pre-ejaculatory fluids also contain sperm, and they start to flow very early during sex play. If you engage in vaginal penetration without a condom, and then "suit up" only when things get hot and heavy, your partner may already be pregnant by the time you get the rubber on. (You'll also have completely negated any protection you'd have had against STDs, had you used the condom properly.) 3. The condom was removed too late. Yep, it feels great staying inside for a while after you're done, but as soon as you begin to lose your erection, your condom loses its grip. Leakage occurs, and it's, "hello, parenthood." 4. Believe it or not, some guys try reusing their condoms. Perhaps the greatest tragedy of this is that people who so obviously should not be permitted to reproduce are the ones most likely to do so. 5. Manufacturing defects. Sometimes, you do everything right, and the sucker still breaks. Although this happens less often than the previously mentioned failures, the odds against it are little comfort when you're the one who falls into that statistical minority. Regarding latex, polyurethane and lambskin: Latex condoms are the most common, and have the best record of protection against pregancy and disease. Polyurethane condoms are relatively new; they have the advantage of not causing an allergic reaction in people who have a problem with latex. Although early tests and polls suggest that they should be equal to latex in performance, it's too soon to be 100% sure. Lambskin is porous, and the pores, while too small to allow transmission of sperm, are more than large enough to permit passage of HIV, which is why nobody with at least half a brain uses them anymore. While we're talking about HIV, et al., let's be clear about one thing: condoms are the only form of protection against the transmission of STDs. This means that even if your girlfriend is simultaneously on the pill, has an IUD, inserts a diaphragm and is in the middle of a visit from "Aunt Flo," you should still use a condom. (There is a "female condom" on the market, which is supposedly the equal of its male counterpart, but so few people use it that it merits little more than a footnote here.) Likewise, even if we're just talking about pregnancy, the best bet is to use condoms in conjunction with another form of birth control: pill, diaphragm/cervical cap, Norplant, whatever. The fact that she's using something does not let you off the hook, because 1) no single method of birth control, barring abstinence, is 100% effective, and 2) you can't be responsible for how reliable she is about the way she uses her methods; you can only count on you. In my time, my partners and I have used most of the available methods, alone or in combination. If you have any questions about what they are and how they work, by all means let me know, and I'll answer as best I can.