Put It On Wrong.
Forget that old wives' tale about confused couples cluelessly rolling condoms onto veggies after sex ed. There are plenty of wrong ways to put on a condom that people actually do in the real world, such as:
- Inside out: It will unroll only with extreme (and possibly damaging) difficulty, and, if you flip it over and use it anyway, stuff that should stay on the inside will be on the outside.
- Too tight: The end of the condom needs some space for semen to go. Up to 45.7 percent of people mess this up [source: Sanders et al.].
- Too airy: Friction against air bubbles makes condoms more likely to break. About more than 40 percent of people don't squeeze out the air [source: Sanders et al.].
- Partial unroll: A condom that isn't unrolled all the way can come off during sex – and it can't do a great job of preventing contact between people's parts while it's on.
- Unrolling before applying: As with an inside-out condom, it's a harder to put on a condom that's already unrolled – so it's also much easier to break.
Here are the right-way basics. Carefully remove the condom from the package and check for damage. Make sure it's right-side up, with the tip of the condom poking up from the center (not wrapping around from the outside). Squeeze the air out of the tip, leave about a thumb's width of space, and place it on the penis (or toy, if that's what's being sheathed up in this scenario). Unroll it all the way down, squeezing out any air bubbles. You can read more detail on the right way to put on a condom in How Condoms Work.