Advice, how to explain to child?

[mother in law]

My gd (whose mother, ex dil, is BPD) had a school concert last night. We (son and I) tried very hard to get tickets but they were gone (it was free and therefore I suspect many had extra tickets) within hours. I rang the school and we were placed on the waiting list to no avail. I rang gd the night before and said sorry but we cannot get tickets but enjoy yourself etc. Gd was sad but I left it at that. Three hours before concert exdil rings son (her ex) and says you can have my spare ticket! This ticket had not been mentioned until this moment. Son lives on other side of large city and had by then made other arrangements for the night as had I. My husband then gets a text from exdil saying: "Gd is sad I am trying to stop her tears. I have offered a spare ticket to son (father of gd) but he won't make an effort, he is too lazy" and on and on it went.

Now be aware the last school event which I wrote about on this site she refused to go to if we were there! Soo confusing for all of us. We have all agreed to ignore what she (exdil) has  said as it is a no win situation and will just result in countless abusive and untruthful texts etc and would probably just result in hardship for gd. However do we address this with gd as we are all pretty sure she (ex dil) will have painted us all very black? And if so how do we explain this to her in a non blaming way? Advice? 

[catclaw]

Hey mother in law 

Hmm, how old was gd again?

My first thought would be something like "you know, gd, we couldn't get any tickets, they were gone. I tried very hard to get some and was put on that waiting list (-is there any possibility for her to see that list btw?-) with your dad. Mommy had a spare ticket, but maybe we didn't communicate it the right way (-which I think is true, at least for one side-) so we just didn't know about that ticket. When we learned about it, it was too late to come over."

And about exdil... hard to say :S "too bad we couldn't come. we were put on the waiting list and we didn't know about the spare ticket."

when I talk to SS about whatever went  wrong on the other side, I try to tell the truth, without mentioning her. She can't take him one weekend because she has better to to? "I don't know what Mommy's doing, but what would you like to do the next weekend?" if he cries and tells us that he wants to go wither way i just say "I understand that, you were looking forward to it, right? Everybody has their reasons. (-which I feel is true, even though her reasons have nothing to do with him-)" And leave it at this... .