What do I do about these house guests?

MY fiance and I bought a house in October of last year, and we are planning our wedding for August of this year. I was already stressed out enough in planning our wedding, but my husband to be decided, without consulting me first, to invite a friend and his gf to stay with us for the summer. They were supposed to get part time jobs while here to help pay for bills and groceries since my husband and I don't have a lot of money. Since they have been here they have only gone job hunting once, she had one interview and didn't get the job. They haven't been active in looking for a job other than that one day. They sit on my couch all day, play video games on my tv that are not multiplayer so that we can all enjoy playing. They have been eating all my food, using all my things, breaking my utensils and using them incorrectly (like leaving a plastic/silicone spatula inside a steaming hot pan to melt and break). They also keep asking us to pay for their cigarettes when we can barely afford groceries because they eat a weeks worth of food in one day. They have not made any effort to contribute at all while they stay here, and don't clean up after themselves. They are selfish, self-centered and rude. They have only been here one month and they are driving me and my fiance apart, we argue constantly because of them and our financial issues while supporting them. I don't want to flat out ask them to leave, as they were invited to stay until after the wedding, but this is not working out for me. On top of it all, this guest was supposed to start school in September and may not get in for the coming semester, so they said they may be staying another 6-7 months (they told us, did not ask to stay). I don't want to offend them as they are otherwise good friends, they are just bad house guests. This is a huge strain on my fiance and I, and our relationship is suffering because of it, and we don't want this strain going into our wedding in a month. What do we do to make them see what they are doing to us without being mean or rude to them?