Back to Your contraception guide. Always put on the condom before there's any contact between the penis and the vagina, mouth or anus. They'll rub against each other, and this friction can weaken them and make them more likely to break or fail. Check the expiry date on the packaging, as condoms don't last forever and may be past the point at which they work. Buy condoms before going on holiday to avoid problems with language and trying to find somewhere to buy them.