Just need to vent!!!

charity
So I have an 8 yr old step son who most of the time is just so damn disrespectful, don't listen hits the other kids etc. Then other times he is good. At school he is not listening and I came up with punishment that we will not celebrate his birthday as it is not mandatory it's a privilege. And his dad thought it was a great idea. And he had 2 months and constantly reminded. Cause all other punishment hasn't worked so today was his birthday and we did nothing for him. And now at the end of the day my husband starts saying he feels bad and it's not right etc. Making me seem like I'm the bad guy here. I feel like if he had a problem with it to begin with he should of said so, but he waits and makes me feel like crap about it now... mind you I'm a stay at home mom to 7 kids and 3 of out of 4 step kids are really disrespectful and dad doesn't see it cause they don't do him like they treat me. So alot of the time he acts like I'm picking on his kids or something as if I don't see them as mine. I don't know what to do anymore...