Time to STOP being a doormat.
Your son, and you.
Meaning, you don't HAVE to let Denny in your house.
You don't have to let Denny act like a brat.
I would have, told him off. In a VERY STERN "Mommy" tone of voice, in a very commanding tone of voice, by now.
And if he laughed in my face. I would have said "Oh goody, you gave me just the reason, that you will not be welcome here anymore." And shut the door.
Your son, needs to learn how not to be a door-mat.
Can't he speak up?
And you are wanting your son to have other friends in the neighborhood.
But, doesn't he have friends... from SCHOOL?
Why only rely on "neighborhood" friends to be his company?
Maybe there is no viable or good/nice kids in the neighborhood, then what? You still want your son to have neighbor kids as friends and to rekindle neighborhood friendships?
Doesn't your son have school friends...that he can invite over?????
And, your son can join other activities.
It does not have to be basketball or Boy Scouts.
What does HE, like?
What are HIS interests or talents?
Get your son involved in other things, besides the neighbor kids that are obviously not, his friend.
At all.
And, when Denny interferes in your son's life.... and anytime your son seems to make new friends... then DO NOT let Denny in your house. I mean, Denny can only "make sure they go away either by arguing with them..." if DENNY IS IN YOUR HOUSE, too.
So don't let him in. Say you are busy, that you have guests in the home, and that he has to go back home.
Why, is Denny allowed to interfere, in your and your son's life?
Denny treats you all like a doormat.
Denny, is controlling your son and you.
Everything revolves, around Denny.
Why?
It does not matter, that they knew each other since they were 4.
C'mon. That doesn't mean they HAVE to be friends and be joined at the hip.
Denny is obviously, NOT a friend.
NO one, has.to.be. friends, when the other is mistreating you.
And, a person needs to realize, when they have OUTgrown... a friend.
And just move on.