You have hidden under Lucia's desk in hopes of getting a good look up her skirt and if you get you can tell her you are trying to fix her desk! She has no idea you are under the desk until she moves her chair back and sees you looking straight up her skirt, she demands to know who you are so you tell her you have been fixing her desk. She tells you how creepy it is that you didn't say anything when she sat down, Lucia notices the bulge in your trousers and very quickly realizes you have been looking up her skirt!