We don't see them often,but when we do it's full of heartache because the boy is so tiny. He is six years old but my 2 year old(his supposed brother)is bigger than him.the 6 year old is only a little taller.my boyfriend is a big Guy tall and round so is this boys mother, but the boy is very petite. The problem is my boyfriend cries because he thinks the boy is malnourished. I truly believe he is not his biological child. What can or should I do?