Oh, I love that! Angel Eyes! 
(That's how I look right now, with my left eye always closed...like a wink.)
I was talking about our wanting "things" (life, people, circumstances) to be different. They are how they are, people act the way they do, and we don't get to vote,...we have no choice. I have spent much of my earlier life anguishing over not wanting things to be the way they were. Whether because I saw other solutions, thought I could fix them or couldn't adjust. It helped me a lot to get that they are how they are. Does that make sense?
Yes it does make sense and I thank you for explaining it. I wish they would change and be different, some of them. They need to. 
In time they do change....maybe not all, but a lot of them do....we did....remember when you were young and newly married? I can't speak for you, but I was a brat...wanted everything my way....wanted to start my own household with my own rules....didn't want my mother in law hanging around all the time, or telling me what I should or should not do....she did that without realizing, she was treating me like a child and I hated that, and hated the fact that she thought, it was OK to interfer with our lives, and suggest we come there or they come here, or would stop by without calling first....
My suggestion would be this....just to play it safe, never ever ask the kids to do something before you ask they're mother....and when you call, or they call, make it a point to ask for DIL and tell her, hey, your coming into the area, would you guys be able to stop by for dinner or a short visit....I wanted to ask you before telling the kids, in case it doesn't meet with your schedule.
Men will say, yes, we'll come, without checking with wife first, to see if the wife made plans but didn't yet vocalize it to her husband. This used to happen a lot to me....I would forget to mention to my husband that I wanted to do this or that on the weekend...we both worked all week....then his mother would call, and he'd say, sure, that's good, then get off the phone and say, we're going here or there on Sunday.
Well, I'd be ticked b/c in my mind, I had that Sunday planned, so, he'd have to call her back and say no, we can't come, wife made plans and I didn't know it....but men forget to communicate things to they're wives....it might not be you as much as you think it is....
I would try wooing her a little...ask her, "would you like to come and visit or come for dinner?" I'm sure it really upsets her when you say something to the kids without asking her first....and it might even seem to her, like you purposely do that to manipulate the situation, b/c you know she might not be able to say no to the kids. I'm not suggesting you are, what I'm saying is, that is how she is seeing it...and thinks your doing, so change it.....ask her first....don't ask son....they are a team, and both must mutually agree, and by asking him, your putting him in the middle. It makes things worse all the way around....I know you had no intention of doing so, but next time, catch yourself...and then call her, specifically to ask her....if she says no, don't take it personal, perhaps they do have other plans...you do have power over this...you have the power to make it better....by remembering, she is his wife, they are a team....and the team has to work together. You know by now what she is like and you know, that asking him isn't a good idea...so reverse the tactics....like I said, the first few times she may say no, but your going to surprise the heck out of her and it will eventually make her feel good. Let me tell you, when things get to this point between to ladies, we don't think logically, b/c we have our emotions and heart involved...what happens is, every time something like this happens, we then take it as a rejection, when it might not be that at all...so now this builds on the past....constantly adding kindling to the fire....and the fire builds and builds...and we perceive things not as they really are...b/c we're hurt, and we know there is friction between her and I....so, we tend to blow things way out of proportion.
Try it, it might work....doesn't hurt to try next time....see if it fits....might make you feel good to...in the meantime, have a great time with your hubby....
Hugs
Creme
