Can anyone help me to understand

I don't understand the significance of the 2 bathroom scenes?

Near the beginning of this movie, Charlotte is in a public bathroom and her husband is in there with her.

They were discussing the death of his first wife, Stella the first time (if I remember correctly)

The second time, they were discussing the death of the husband's friend (the one in love with Stella).

I saw this movie by chance several years ago and it bothered me to see Charlotte peeing as she was telling her hubby that she was sorry for the death of his friend.

Those scenes were too much like something David Lynch would throw in.

I can see this movie didn't go over too well just by the lack of comments on the board but was hoping someone could help me.

It seemed unnecessary and did not add anything to the story.

To me, the movie was interesting but I feel that Stella got what she deserved