Just a few initial thoughts...
Grandmother is stronger than Grandfather. The I originally saw the skirt in connection with a wedding.
The stain is what Grandmother shows as a secret, something that has not been spoken of. Grandmother is saying that it's time for this to come out. It's time for this to be dealt with.
I had the feeling that this was an old secret, something that happened pre grandparents wedding. Perhaps something similar to what you experienced.
Grandfather is not in agreement. Grandfather expresses sadness, he feel this is something best kept hidden, or something are better left alone. They are, on this matter anyway, split like the colors of the skirt. Blue is the color of emotion so this is an emotional issue.
I'll pop in later as messages come through.
I hear a name...
Marta, Martha, Margaret maybe
Grandmother has shown me the same image twice.
She is at a window watching two children playing outside on a narrow road in front of her home, a boy and a girl of similar age playing, kicking a ball.
Grandfather is there but very removed/far back from the seen. He sees this from a different angle, he is not inside of the home or even on the street. But I sense him there. This weighs on him.
There are other details regarding these children. I'm not sure if you recognize them, or have an idea of who they might be...
I don't believe you told me whether or not your grandparents are still with us, or if they have passed.
Thanks for offering
Well, I don't remember everything now. But the theme was there was my grandma there and my grandpa. Basically, in this dream I was afraid my grandfather was going to die as he was so weak and my grandma - I don't remember clearly. She was in a much better shape but still not totally ok, I think.
In a dream your feelings are your real feelings. You may have seen or heard something that led you to believe that your grandfather did not have much time left.
And at one point I remember I took a skirt from underneath the blankets in the bed she was lying in and that skirt was kind of dirty - it was a skirt that wasn't worn by anyone, or at least not often, it looked like it was washed and even ironed but stained with something.
The skirt being taken out from under the blankets shows something that had been hidden, is now being revealed.
It's dirty, imperfect. Something that might cause distress or embarrassment.
The skirt having been washed and ironed shows an attempt to straighten this situation out.
A few nights before that I also had another dream - similar in the way that I was worried about my grandfather and that no one was really taking care of him. There was lack of communication between him and the grandma, which wasn't the case in real life. I also remember the colour navy blue.
Seeing your grandparents brings a sense of strength, comfort, safety and family, even though they are frail in the dream. And the shade of blue can signify loyalty/family loyalty which is often strong in with our elders.
I wonder if your grandmother knows what this stain is from. I wonder if she helped to straighten it out.
Whether or not that's the case, it would appear that there is something that you need to acknowledge and deal with.
It could have to do with your ex since you wore the dress with him, and seeing the dress may have triggered these feelings and dreams.
I hope that there is something here that makes sense to you.