....by his son and DIL.

There are so many things unfair to you and your DH about the situation you describe. Such as, why on earth would anyone fix a hole in a wall that someone made by punching? These adults are calling up your DH and crying, ugh! They are trying to manipulate your DH big time by crying. It is working though.

Your burger date night with DH has been ruined by their requests, which is unacceptable as far as I am concerned. This reminds me of a time not long ago when YSD actually said to my DH that he should move in with her and be a nanny to their child, right in front of me while DH was ill. She never even stopped to think that daddy was ill, nor did she care. All she cared about was getting daddy to be a built in babysitter for her and the gskid.

I cannot believe these self-centered adult skids just think their parents should be at their beckon call each and every time they need something done or a babysitter. it is wrong, just plain wrong. 

If it were me, I would compile a list of what needs to be done around the house and give it to DH. Let DH how you feel about this and how it is so obvious he is being taken advantage of. Ask DH to tell the adult skids or tell them yourself they need to hire repair people, etc. and that your DH is not their bleeping handyman. 

Plan a nice long vacation for you and DH and get away from these miserable people who are using your DH.

Your DH is being manipulated by his man-child and DIL. DH should be enjoying his retirement and not working for free for anyone.

It sounds like your DH is, in essence, still trying to "buy" SS's love by being at his beck and call. And that he will do anything and everything to be part of SS's life. I imagine that if you protest, he will only dig his heels in and proclaim that you hate his kids. So...

There is nothing you can do to change your DH's behavior - you can only control yourself. Is there a hobby in which you've been interested but never had time to start? Now is the time! Take a class (foreign language, gourmet cooking classes, crocheting, yoga, meditation), volunteer your time to charity, join a group (book club, etc).

What a pair of dysfunctional, codependent men. Wow.

All you can do is focus on how your DH's activities affect you. He changes plans he has with you without checking with you first? That hurts your feelings, and you tell him how HIS actions affect you. "Honey, when you change our plans without checking with me, I feel like you don't value our time together." See? That's nothing about SS.

Take SS out of the equation completely -- nothing you can do about him and this truly unhealthy pattern of behavior. Although, if your DH gets to a point of being frustrated with his son, I highly recommend individual counseling for him so he develops the tools (and balls) to use that magic word "no."

Enabling is the key word here.  Your SS and his wife say jump and your DH says how hi.  They got a good thing going, why would they stop?  And I wonder, is your DH TELLING SS to call him if he has plumbing problems, roofing problems etc.?  I wouldn't be half suprised.

And I don't know... how often are adults expected to call and chat with their parents?  I do find myself guilty of more frequently calling my mother because I need her to pick up BS or BS is asking to go see her or whatever than I do calling her just to chat.  I do try to involve her in things like if BS and I are running in a 5K, I'll let her know and she'll sign up and walk it.  We also went on a couple trips together .. things like that. 

I DO feel guilty sometimes when I have gone a couple of weeks without talking to my mother because I'm busy and honestly I can't stand talking on the phone. Maybe your SS thinks that the interaction he has with your DH when DH comes to fix things, babysit their child etc. is enough?

I would be okay with the babysitting as long as it didn't turn into fulltime and the kids weren't trashing my house.  Hopefully the babysitting will be at SS's house.