7. The Mistake: You’ve had the same condom hanging out in your wallet forever.
The Potential Damage: Using a condom that hasn’t been properly stored might get you into a situation worse than the sexual slump you just endured. According to Herbenick, extreme heat or cold can damage the latex used in condoms, so the best spot for stashing them is a cool, dark, dry place—like in your nightstand—or a small, hard case (think: one made for business cards). And if you’re really trying to be a douche about the whole thing, there's alwasy this $200 Swarovski crystal condom compact.
8. The Mistake: You’re not putting lube inside the condom.
The Potential Damage: Those marathon sex sessions you’ve been having (nice work, bro) are bound to wear down the condom, making it dry and prone to ripping. “Always use lube inside the condom. It prevents breakage and plus, it actually feels so much better for the condom wearer,” says Andelloux. Remember: check the type of lube before you apply, and just use a drop—too much can make the condom slip off.
9. The Mistake: You take the condom off before the sex is over.
The Potential Damage: If you're patting yourself on the back for using a condom in the first place... don't. Taking a condom off too early on into sex "can directly compromise the efficacy of condom use," according to a recent study from The Journal of Sexual Health. But you know that, silly! So if you play by the rules and keep that sucker on the entire time, it's 98 percent certain (see no. 6) you won't have to worry about becoming a daddy. (Just be sure you hold the base of the condom during withdrawal to make sure it doesn't slip off or leak you-know-what.)
10. The Mistake: You don’t need condoms—you’re a “pull-out pro.”
The Potential Damage: You might think you have impeccable timing, but even if you do pull out in time, it’s still possible to get her pregnant. How? According to Planned Parenthood, your pre-ejaculate can pick up enough sperm left in your pipes from your last ejaculation to fertilize an egg. Whoa. Now, urinating between ejaculations might help, but as they say, it’s always safer to wrap it before you tap it—and the risk-taking for your non-sexual adventures.