Was it Bree?

However, she was not in the position to wish for her benefit. Bree was feeling very guilty about what they did and if Andrea were to be thinking of herself, it would make her appear more selfish than she actually was.

Being in love had found a way to transform her into a person she didn't even recognize. Now she felt things at a larger scale. Now she was thinking of a handful of consequences before she made a decision. Now she was sentimental about everything around her. How does Bree expect her to live now?

She never thought having sex with Bree would lead to a ferris wheel of regrets.