need advice!!!!

Brandi 🧜🏼‍♀️🍍🦄 • momma to my first born Carter 7/3/11 • bonus momma to 2 more boys Stephen & JJ • momma to an angel baby 3/3/16 • and momma to my rainbow baby Aria 11/29/17 •
my fiancé has 2 boys and I have 1. his two are 5 & 2 and mine is 5. 
when we first got together he used to make a big deal about me "babying" my son, and yet that's all he does with his youngest. and if i ever try to say something, i'm in the wrong. 
little back story, i was pretty much a single mom.. it was only me and my son for 4 years! and then i finally met the person i want to spend the rest of my life with. so yes, i'm not going to lie, my son was spoiled! and i definitely did baby him and it was hard to break away from that. but i just don't understand how my fiancé could give me so much grief and then he does it with his youngest son! 
like for example today jj wanted some oreos so i let him have 2 and he spit them out, and yet my fiancé didn't do anything about it..  then i get back from picking up my son from school and he has jj asleep on his chest while using my blanket.. which wouldn't be a big deal, but he gets mad if anyone uses his blanket. and once he woke up, my fiancé would not put him down... 
he literally said to jj "you can't go play bc you two shouldn't play together" what in the actual fuck?! how are they ever supposed to get used  i each other if you don't let them play?? 
after dinner he was squirming for like 10 mins and my fiancé goes "what's wrong" and i looked at him and said "uh he wants to be put down." so he puts him down and tells him to go play. well low and behold, within 20 mins jj threw something at carter and instead of my fiancé just telling him he can't do that, he picks him up and brings him back out in the living and has him right next to him.. 
am i wrong for being frustrated?? bc i feel like he doesn't losten to anything i say, or he will just take it the wrong way.. is anyone else in a similar situation?