he is 17 months and sits in a highchair. he always wants the food off my or ds1's plate even though he has exactly the same as us. when he tries to reach it and whinges for it, i ignore him and he throws his own food on the floor, also his cup aswell. should i pick it up and give it back to him(floors are clean) or just let him see that if he throws his food he doesn't eat?