3. The Mistake: Your hands are sweaty, so one of you tears the condom package with your teeth.
The Potential Damage: Using items like knives or scissors—even your teeth—to open a wrapper will make it very easy to mistakenly poke a hole in the condom. (In one study, dudes who did so were about three times more likely to encounter breakage.) Think about it—do you really want sharp objects coming anywhere near the super-thin barrier that stands between you and fatherhood?
4. The Mistake: You put the condom on—but don’t leave any space in the tip.
The Potential Damage: If you covered up a faucet with your hand and turned it on full blast, where would the water go? See what we’re sayin’? It’s not rocket science. So leave approximately half an inch at the top of the condom to properly “catch” your sperm, says Herbenick; without this wiggle room, you’re risking breakage.
5. The Mistake: You don’t use a condom because she’s on the Pill.
The Potential Damage: If you’re in a relationship, you should trust that she’s true to her word, but for a one-night stand? It’s not worth the risk. According to the Centers for Disease Control and Prevention, birth control pills are between 91-99 percent effective in preventing pregnancy—but the Pill plus a condom gives you close-to-perfect protection. Your call.
6. The Mistake: You were wasted and couldn’t find a condom...so you didn’t use one.
The Potential Damage: Sure, it’s an understandably awkward situation if you’re about to “get it in” and can’t figure out where the hell you put the condom. But is it more awkward than becoming a daddy if you’re not ready for a kid? Get off your ass and search a little harder, or walk to the store and pick up an extra pack. According to the World Health Organization, with perfect use, condoms prevent pregnancy 98 percent of the time. That’s pretty damn good.