The person who treats Pavel with the most disrespect is Lieutenant Kotler, not necessarily Bruno's family. In chapter 7, Lieutenant Kotler is the one who tells Pavel to help Bruno with finding a tire for the boy to make a swing, and along with that, he can't finish a sentence without calling Pavel a bad name. Gretel, Bruno's sister, does not say anything mean to Pavel, but she doesn't stop Kotler from being rude to Pavel either. (Guilt by association, one might say.) Bruno remembers in this chapter that his father thinks that Pavel is a good waiter, so his father probably doesn't disrespect Pavel as much as Kotler does. That's not to say that Bruno's father "likes" Pavel in any way—it just means he's not as immature or rude as Kotler is.
Having been a doctor before the war, however, Pavel's training and good nature hold him to a higher standard when Bruno gets hurt in chapter 7. Bruno thinks he might bleed to death, but Pavel calms the child down, takes him into the house, and takes care of the wounded knee. When Bruno's mother comes in, she thanks Pavel and sends Bruno out, but not before Bruno overhears her thanking Pavel. The mother even tells Pavel that she will protect him by saying, "If the Commandant asks, we'll say that I cleaned Bruno up" (85). The boy's mother shows kindness towards Pavel just like he showed kindness to her son. Unfortunately, the kindness must be kept a secret because of the fact that Pavel is a Jew. Pavel actually risked his life by helping Bruno. That's more than the mother risks by covering for him, but at least she does something more than her husband, Kotler, and Gretel would have done. Therefore, Pavel's treatment of Bruno is better than how Bruno's family treats him, but there is an element of kindness from the mother. And even though the father and sister aren't particularly rude to Pavel, at least they aren't as bad as Kotler is.