Watterstide I am sorry this is happening & believe you are on the right track to finding a solution. I give you a huge hug for being understanding & caring. We had a min.Schnauzer & she would sometimes go pee on our DS's bed. Never on any other bed, just his. He loved that girl and we would totally strip the bed at night when he would go to crawl in and find it wet. LOL Finally we figured out that she would be tired and ready to go to sleep in his bed but....he would be gone! So she peed in it. She wanted him to be there to go to bed with her, when she got tired.LOL Demanding little cuss. LOL Had to resort to shutting his door until he went to bed. Problem solved. LOL Maybe this could be the same thing for your little guy? Anxious for you to find out the problem and a solution. Hang in there.