Someone didn't pull it out in time.
None. The light bulb shall never burn out. (OK. It's more cathartic than funny...)
A crackhead buys crack so he can put it into his pipe and burn it. A John pays so that he can put his pipe into a crack that might burn him.
They pull out on time.
If you lay them right the first time, you can walk all over them for years.
With the stock market you can only lose when you pull out.
Because a vasectomy would heal in seconds and he doesn't look like he'd wear a rubber or pull out.
In all 3 cases, someone forgot to pull it out.
Someone that didn't take it out in time.
Failure to pull out in time