the ex pissing me off

Let us say that the ex and I do not get along. We have two nice and wonderful children that she uses as weapons. But here is an example of some psycho games I go through. I have the children on Thanksgiving, no other real holiday. I had to fight to get the children at 10am on Thanksgiving. For years it was 3pm on Thanksgiving day. She gets them on Easter, so I have to return them to her on Sunday (she never delivers nor picks up the children, that is another story). She states that she wants them at 7am to go to the 8am Mass, meaning I will have to wake them at 615am and get them in the car and going by 635am.
"Is that the only Mass on Sunday?" I ask,
"It is." she answers.
I call the church, there is Mass at 8am, 930am and 1100am.
Now, this is not the first time she has told me something about her church that was not true. Now, you may think that this is just a mistake on her part. Except that we all know that they announce these things early and often in the church. Today I am going to tell her I will return the children at 10am on Sunday like I pick them up at 10am on Thanksgiving. This may seem petty on my part, but the hell and court proceedings that she puts me through makes this a dot on a page of a tome that she has written.