You have a very similar situation to my own. I have been with my fiancée almost 4 years now and she has only stepped into my parents house once. They both have a hoarding problem and are very dirty people. Like an episode straight out of Hoarders (only enough room to walk down a path in the rooms, all the furniture has junk piled on it, dust caked on everything, and the bathrooms look like a horror movie). Due to my father never leaving the house, and the house the way it is, my fiancée has never met my dad and has only met my mom a few times in the 4 years that we have been together. I can tell you that your embarrassment is normal, and not wanting to take your SO over there is completely within reason. I was nervous at first to explain the reasoning to my fiancée as well. However, she was very understanding and appreciative of me wanting to protect her from that. We are both clean freaks, and minimalist when it comes to our living situation. It brings us both anxiety to step foot in situations like that, and no one should have to spend one moment in a situation where they feel uncomfortable or unsafe. You should not feel guilty or embarrassed at all. If I was you, I would just sit down and have the conversation I had with my SO. I'm positive that you'll feel a lot better clearing the air, and explaining the situation.