Hi, My baby boy is 1.5 years old & he pinches hip of mom who wears saree. One day when I worn saree he even pinched my hip. He does to men also. Why?

Exploring? At 1 1/2 your son is learning lots of things about his world and touching is one way to do that. Pinching/biting can be normal ways to explore; however, they are painful to the other people so we tend to want to discourage it. Tell him "ouch, that hurts, no pinch" and move his hand away. If you see him going to pinch intervene before he does it and say "no pinch, that hurts".