Why was Lou Ann angered by Angel's disposal of the Tug Fork water?

Granny Logan has a coke bottle filled with Tug Fork water for baptizing the baby. She reminisces about how Lou Ann was baptized in Tug Fork, then complains about how Angel is working on Sunday and how she should not expect better from a "heathern" Mexican.

Lou Ann buys tomatoes from Bobby Bingo's truck. He asks Lou Ann if she knows his son, Bill Bing, who sells cars on TV, but she admits that she doesn't have one (her husband took it to his new apartment). Bobby Bingo brags about how his son says that he could buy him a house in Beverly Hills.

At home, Lou Ann sees the coke bottle and tries to remember being baptized in Tug Fork. Angel comes home while Lou Ann nurses Dwayne Ray. He asks whether she has seen his belt buckle or Toros cap. Lou Ann can smell beer on his breath. He asks what is in the coke bottle, and when she tells Angel he pours it down the drain. As Lou Ann nurses her baby, she feels as if he might such the pain right out of her breast.