Serious answers please about condoms and safe sex?

They can break for a lot of reasons, mostly from putting them on wrong of if they are expired or stored improperly (in a wallet for a long time, in really hot temperatures, etc) or possibly from friction (use lube to help with friction issues). Never use two condoms at once, it makes them much more prone ot breaking. Avoid breakage by storing them in a cool safe place, by putting them on properly (pinching the tip to allow room at the top), and by using enough lube. Trojan and Durex are two of the most popular brands. I like the Trojan Ecstasy ones the best. If a condom is used properly it will protect you from STD's very well but they are not as effective at preventing pregnancy (something like 85-90% I think) so it is good to use the pill in addition to condoms. It is a good idea for you and your partner to get tested for STD's before having sex just to make sure you are both clean. It's good that you are trying to be informed and safe!