My lighter is hissing so I'm assuming its been punctured in some way. Is that dangerous and hazardous? (probably so, hence the stupid part) If so can I just throw it away in the trash can or should I toss it into some kid's mouth?
That's actually happened to me before. You just need to microwave it for about 30 seconds and it'll stop.
Get a second lighter and burn the first lighter, so that the plastic will melt and seal up the leak...