I'm a chick and I smoke....I would never be that rude. I'm guessing your dealing with 16-22 year olds here and sometimes they just need to be schooled cuz they kind of selfish at that age.
some folks just don't know...send them directly to www.smokingwithstyle.com or better yet when they come over be looking at the site. Make sure you read out loud and laugh about the "no moochers" part with your friends who match. Point at friend who doesn't and say..."dude your slacking"
They may not have a hookup, or be shy to ask you for one, so they smoke out with you assuming it's all good. Tell them to at least provide munchies or papers or something if they can't get or can't afford weed. (it's only polite) And next time michelle wants to smoke a bowl tell them that your stash is low and if they would like to put five on it or go in with you on a sack they are welcome too. Speak up more about it, and not just you, the friends who match should also be giving the non-matchers hell for their mooching ways.