My biggest fear is my SO..? Advice *

Let me get straight to the point, no I'm not being abused, but I do fear my SO. 
I'm pregnant, like super pregnant at this point and more and more I'm noticing my hubbys need for attention. Whether it be from me, his family, my family, anyone. Just attention. 
Let me be more specific: he's 23 years old, he's Latin (don't know if this has anything to do with it), but with that being said he's the youngest child of 2. He has an older sister and his mother BABIES the living HELL out of him. No, it's really bad. He'll sneeze and she'll want to take him to the hospital. He'll walk in the house and it's "AYEEE MY HANDOSME BABY. MY SON HERE HE IS" when we fight she always needs to find out why we got in a fight and make sure HE'S ok. His whole life they let him get away with murder: he could curse at his parents or yell and they'd bow down to him and give him what he wanted. He got away with using drugs, got himself out as he got older thank god but they knew and didn't want to push him away by punishing him! And I'm NOT anything like that. I was raised "yes mam" "no sir" respecting elders, waiting my turn, and was spoiled but NOT babied. 
SO fast forward to now, I love my MIL even though the way she treats him gets on my nerves and she adores me, he's a great hubby and does anything for me and for our unborn son but I fear that he's going to get jealous of our son. His dad joked today about how he's the baby that's always gotten attention and now that we're having a baby the baby will get all the attention and he actually kind of threw a fit and got mad? I noticed it but I don't think anyone else did. He kind of got an attitude. I mean he LOVES our son already and spoils him and says how excited he is but I really do fear that he's going to end up jealous of the baby..
On his birthday last month his parents gave him a card and a huge bag of baby clothes that they went and got our baby and he was mad that he didn't receive a gift...maybe I'm just insensitive and think he needs to grow up but anyway, 
Has anyone else ever dealt with this? What did you do? What would you do? (I tried talking to him about it and he got mad at me for being honest and telling him he needs to grow up)