Use the Wrong Lube.
Latex pro: It's basically rubber, so it's stretchy. Latex con: It's basically rubber, so it's grippy. What it has in stretch, it lacks in slide.
Lots of rubbers are pre-lubricated to compensate for their annoyingly high coefficient of friction, but many people need (or want) things to be slipperier, or want a different lube than the ones that go on at the condom factory. But most of the slick substances likely to be around the house – like petroleum jelly or vegetable oil – don't mix well with condoms.
There are almost as many lubes to choose from as there are condoms, but water-soluble lubricants are the only ones that team up well with latex. Lubricants made with oil or petroleum products will weaken latex condoms, making them likelier to break. Water-soluble lubricants are also easier to wash away, which makes it easier to wash off any sperm or pathogens that might have gotten in there.