Was this a proper move by the ex at my fiances daughters wedding?

I was brought down the aisle by the groom and seated next to my fiances ex-wife and her new husband to my right. The ex-wife gave her husband a disgusted look and she made him trade places with her so that her husband would sit next to me and she to the right of her husband instead of her sitting by me. This was my first time in meeting this woman. I didn't really catch it. A friend of my fiances who was a speaker at the wedding was sitting in another section of the church saw it and he mentioned it to me a few weeks after the wedding.