Since you asked, I do think it is odd that your grandchildren sleep with you if you have other accommodation available for them. Also, a nine-year-old should be able to bathe or shower alone. I would worry more about lack of independence at that age than anything improper, but at age 9 I would expect a boy to be more modest than you are describing.
Free printable topographic map of Morro Bay (aka Moro Bay and Bernard's Bay) in San Luis Obispo County, CA including photos, elevation & GPS coordinates.
3pm: The Morro Bay, CA forecast for Feb 14 is 64 degrees and Partly cloudy. There is 42 percentage chance of rain and 8 mph winds from the West-Northwest. 6pm: The Morro Bay, CA forecast for Feb 14 is 55 degrees and Partly cloudy. There is 58 percentage chance of rain and 7 mph winds from the Northwest. 9pm: The Morro Bay, CA forecast for Feb 14 is 52 degrees and Partly cloudy.