In this week's Torah parsha, Vayeira, in Breishit 18:13, Saying
וַיֹּ֥אמֶר יְהוָ֖ה אֶל־אַבְרָהָ֑ם לָ֣מָּה זֶּה֩ צָחֲקָ֨ה שָׂרָ֜ה לֵאמֹ֗ר הַאַ֥ף אֻמְנָ֛ם אֵלֵ֖ד וַאֲנִ֥י זָקַֽנְתִּי׃
Then the LORD said to Abraham, “Why did Sarah laugh, saying, ‘Shall I in truth bear a child, old as I am?’
Rash"i says that because of the sake of peace (Shalom Bayit), God changed the truth and phrased it that Sarah said the she was old, when in fact (see verse 12) hse said that her husband was old.
From here, rabbis learned that one may lie for the sake of peace, one of them being peace between spouses.
So, under what circumstances may one lie or convolute the truth (part true, part false) to his / her spouse? Some examples:
- May one lie about household finance situation?
- May one lie about the way the spouse looks? (Wife puts on an outfit and asks, "Does this make me look fat? Do you like the color, fit, etc.?" Let's say the husband doesn't like it but knows wife would be annoyed hearing the truth.) or the way food tastes, something s/he did incorrectly, etc.?
- May one lie about one's health to prevent worrying or upsetting his / her spouse?
There are numerous examples. Is there any guideline or set of conditions that explains when one may be allowed to lie? Also, should / can one tell a complete falsehood or should he tell a partial lie. (E.g., if he doesn't like his wife's cooking, can he say he likes it totally, or should he say, "It's not my preference, today.")