My family room is directly below my master bathroom. After my wife showered this morning, I noticed a relatively small, round wet area around a nail in the ceiling drywall. The spot is directly below the bath tub. The spot spread out about 2 inches around the nail and was almost a perfect circle. The bath tub has not been used in over a week; we use the shower. While the shower and tub in the bathroom are separate, there is a small wall shared by both. Inside the shower, the tile grout has disappeared between the glass wall looking toward the tub and the first row of tile, leaving about a 1/8 inch space. I also noticed that the two tiles in this same area are cracked, leaving a 1/16th inch space. The tiles are about 6 inches by 6 inches. It is now about 5 hours since my wife's shower, and the spot is drying. My first instinct (which I avoided) was to cut the ceiling and try to identify the leak. I called a plumber but they cannot come for two days. In talking to some people and reading other postings, it seems as though a regrout could solve this issue, but I do not want to put a bandaid on a wound; I would rather heal it. The house is only 7 years old. When I climbed a ladder to my ceiling, I also noticed two seemingly older leak spots directly under the shower. Any thoughts would be much appreciated.

If you are afraid to tear out the drywall then regrout. Use a premixed stain proof grout. If it is a drain issue that spot will get wet again and you'll have to pull down the drywall to do a proper fix.