B.N.
I feel for you J.. My 21 month old pees thru his PJ's at least 3 times a week and he wears overnight diapers AND plastic pants over them. My doctor told me that when they sleep they are obviously relaxed so they let go and urinate. As long as your son is still taking in a good amount of fluid and isn't showing any signs of dehydration don't worry about it. Doctor also said that it is a "good" sign as they are starting to learn to hold their urine and could make for easier potty training. Fingers crossed!!