Are you tickling the boy on his stomach or back? I know that boys on t…

Are you tickling the boy on his stomach or back? I know that boys on their stomachs, but it's not comfortable for me lying on my back. Is there anything wrong with that? And a second question, the child starts crying while bathing, mainly when we wash their hands and neck. The water is the right temperature and the bathroom temperature. What could be the reason?