D.H.
Been there.....isn't it just great!!! Oh my goodness.........First of all, have a talk with the oldest son...........tell him he is being a bad brother and mentor for his youngest sibling. He may not care, but you can try.........maybe have the older spend more time with the younger one........like babysitting for a bit, an hour or two while you do shopping..........
If that doesn't work, you have to tell the little one, that he is too young.......and when he gets to be older like his brother, he too can do things that he doesn't do now...........also, you can tell him that older brother is being very disrespectful, which you will have to explain why that is bad.........and why he shouldn't want to do those things..........he's a good boy and you don't want him to act like that..........And just keep repeating it OVER and Over again. That's what I had to do........eventually the little one will start ragging on the older one.........which doesn't help with sibling love, but it did make the older one think for a bit, and eventually they worked it out. As the youngest gets older, he will start asking why do you do that, or say this.........the older one gets tired of the questions and either stops or leaves the younger one alone..........
With all that said, it will be ok.........they will still fight when they get older, but they will love each other and laugh about all the things they did as kids, mine do and they are in their 30's now....
Good Luck, hang in there and take care.