Id like to say something on behalf of the children

Well, because that sounds dishonest, to start with. Yeah, it sucks when dad doesn't show up, but that's the truth. I don't think protecting my kid from knowledge of her dad's shortcomings as a parent is my job.

Also, I think most kids like to know what to expect, and sort of throwing a visit with dad on them unexpectedly sounds like trouble - there's no time to prepare, or transition.

My kid is ten. Her dad spent the first four years of her life in prison, and the last two homeless and living in his car. At this point, she would really prefer that he disappear for a while, because whenever he comes around he either says negative stuff about me, or about her, or both I suppose there are things I could have done to keep her from knowing what an ass he is, but I didn't. I didn't go out of my way to let her know, and I didn't tell her he was an ass, but covering for him isn't my job.

FWIW, Rain is pretty darn happy with life with the two of us

Dar

I can understand both points of view.
I tend to stay out of the relationship between my kids and their dad as much as possible. If he lets them down, it's between them. I cannot change my X's behaviour, therefore, I can only be there to help the kids deal with whatever they are feeling after interacting with their dad.
I can appreciate how difficult it would be as a child to look forward to a visit and then have it not happen. It must be difficult for kids when that happens, however, I don't think that holding the truth from them or trying to "protect" them from the reality of their father is all that good either. I think kids "get" what's going on, even if we don't discuss it with them. I would think if we didn't tell them, they may not feel as safe talking to me (like they would sense I wasn't being honest about things or whatever).
The other thing I thought of is this.....what would be worse for a child? Knowing their dad said he was coming & didn't or just thinking their dad doesn't ever think of or want to come spend time with them? If he doesn't come & nothing is said, the child may assume that their dad doesn't even think about them or think about coming. I'm not sure that would be easier for a young person to handle either.
What I have figured out is that no matter what, I can NOT change my X and I cannot get into his relationship with the kids. All I can do is continue to be a safe, loving, secure, and honest place for them and help them deal with any disappointments or struggles they have along the way. I try to provide the best role models and lots of loving, supportive people in our lives. I guess that's my job as a single mom.