A note about the scores before we continue...

A brief explanation of the bars on the right.

Faith: Beth's loyalty to Brian and their relationship, whether solely from love and propriety, or because of fear, or other factors. When this is high, she won't stray without compelling reasons. It will take ****, or ****, or some other form of persuasion for her to go along. As it falls, her ability to resist temptation to stray falls, and it will require less effort for her to cheat, and go further with her cheating, and she will be more likely to initiate the infidelity rather than simply going along at the prompting of someone else.
Once it's established by her upbringing, sexual formation, and career, Faith only moves when Beth acts. It goes down when she strays and up when she chooses to either avoid temptation or reject opportunities. If Beth is not making a choice to do or refrain from doing something, Faith cannot move. There is no set level of Faith at which Beth will commit certain acts: circumstances and scenarios will have different thresholds, or sometimes have no threshold at all, but in general, the lower the Faith, the wilder the girl.

Shame: Beth's attitude towards her illicit fantasies, thoughts, and actions. Is bolstered by her love towards and happiness with Brian, and undermined by dissatisfaction with him, or by infatuation with someone else. When high, she will feel guilt for even fantasizing about straying, though this may not stop her from her wayward thoughts and deeds. As it falls, she becomes less and less conflicted about her cheating ways, and when very low she will even revel in her cheating. Shame can be low while faith is still high: in this case, Beth may enjoy her fantasies and flirtations and even crossing the line with guys, but she won't go further out of fear or self-doubt.
In contrast to Faith, Shame is more of a function of the actions of others. A change in Shame will usually be hinted at in the text by Beth's thoughts. Shame can be a gating variable for certain acts, usually ones that will put her in a position to engage in Faith-lowering choices.

Arousal: Beth's current level of sexual need. When low, she's satisfied in her need for sexual fulfillment. At mid levels, she is starting to feel frustrated in her need for sex, but not necessarily craving it to the point of distraction. When maxed, she is gagging for it, with a **** need for sexual release. Engaging in sex with Brian that is not satisfying will at worst do nothing but leave Arousal where it is. Self-stimulation can lower it a little. Having an orgasm with someone else, whether Brian or not, will usually take a hefty chunk off, but even just giving a blowjob can help if Beth enjoys herself.
Arousal could be a minimum requirement for certain scenes, though in general, even very high Arousal will not **** Beth's hand completely into a illicit act. There might be a choice between a bad act and a somewhat less bad act, but there will at least be a choice.