my stbx was stepdad to my son and he always treated him differently than he did his bio daughters that we have. It may have been because his bio son is all the way in FL and he never gave the child any thought except on holidays or whatever and then barely recognized him. I don't know. I do know that he seemed to resent my son for something and I never quite figured out what because he came into the picture when my son was an infant and I thought that he would love him like his own but soon got the realization knocked into me when he called my son bad names. Then after he left, he has had absolutely NOTHING to do with the boy and he is such a good little boy. I don't understand it myself as I was only stepmom to his son who lived so far away.