I never knew this <<Don't re-use a condom if you start putting it on wrongly. The FPA says this is one of the most common mistakes people make when it comes to contraception (and condoms are the second most popular contraceptive, so that's a lot of mistakes). They start rolling on the condom, realise it is inside out and isn't going on properly - so they take it off and put it on the other way. Wrong, wrong, wrong. You might have got sperm on the outside of it, silly! Now you're going to get sperm exactly where you don't want it.>> I wonder just how many "but we used a condom, I don't understand!" accidents are because of this?