Condom. Agree with Dr Livingston. Being thin does not mean fragile. Condoms that are past the expiration date may have v burst strength, v elasticity & may leak. Condoms may also become degraded if kept in a hot place (like your wallet). Using an oil based lubricant or lack of lubricant can also ^ risk of breakage. Wearing a condom that is too tight, incorrect application or having a partner with a very.