I really want to be selfish with my son...my husband is selfish with my step daughter and I'm not…

I really want to be selfish with my son...my husband is selfish with my step daughter and I'm not gonna lie, I usually get jealous because I didn't have anyone to call my own that is half of me...I wanna be petty and give him a taste of his medicine and I know it'll be bad because I'm having a boy!! He gonna be all mine