How Short Of A Leash Are We Talking Here?

Disclaimer: I am very aware of the fact that I am not a parent (thank god for that one.), nor will I be a parent for a while to come. Therefore, my opinions do not come from personal parenting experience, but my experiences from being... parent-ed.

As a parent, one would hope you want to be there for your child at all times, ready to help, or make sure they don't do stupid teenager irresponsible things, that all teenagers will do/have done at one time or another. Usually, its easiest to just let your kid stay at the house, invite people over there, so as to keep track of the hooligans. Am I right?
For New Years, I'm having a few people people over. Not a party by any means, but a gathering of friends. But somehow, I'm not supposed to supply any food for the guests. Que?? Is it better to not spend any money and make someone else's parents provide food at someone else's parent's house, or to spend a wee bit o' money (that I earn, I have a job), and keep the teenagers in your own line of focus?
I want to hear your opinions on this one. And for that matter, any post to come. I, being a bratty teenager, love to argue, so lets hear your thoughts!

:)