Giant Spider

I have a big spider living on the edge of my kitchen door.It's about the size of a small mouse. It has built a web across my porch light, which is probably how it got so fat. It's big enough to almost be some kind of gross pet. I would be happy to not use that door, but I am having an "open house" on Sunday, and I am not sure what to do about the spider. Should I put up a sign? If I say, "Do not open the door, there is a spider" people will think, oh come on, there are a million spiders, I will open the door. This scares the spider, who likes to sit on the edge of the door where it is warm, and then it runs up the web and tries to make itself small and inconspicuous so it is the size of a quarter instead of a golf ball. It's on the left side above the railing and under the awning, but it is right at eye level. I have taken a couple of bad pictures of it, but to get a good one I have to get closer than either the spider or I are really comfortable with. If I say, "Do not open the door, really huge spider, do not disturb", then they will not buy the house because apparently we have gigantic spiders and there might be many more sleeping in the closets or whatever. I could say "Do not open the door, there is a giant spider outside and you will scare it but it really is the only one and I am sure if you bought the house the cold will have killed this one and it will not be a problem." Of course I am sure there are a lot of little egg balls all around the back porch now, and I am not going after them because I am busy and no way I am reaching under the porch, because there are spiders. Really big ones.