my shower on my third floor is leaking into my living room and in the basement. We had a plumber here who checked the pipes and they are fine, we caulked and that still did not stop it. It only leaks when someone is standing in the shower, it does not leak when the water is running and nobody is in the tub. We just moved here a month ago and the previous owners do not remember who did their remodeling, so we have to start from scratch. There is no water on the floor in the bathroom, but my living room ceiling has a large water spot and it drips about 2-3 cups into my bucket in the basement (directly under the spot in the living room) Please help!