What do you think of trivial or white lies in a relationship?

For instance you had the worst and most stress day at work, your partner asked you and you tell them your day was a bit stressful but ok overall. You don't elaborate too much details nor tell them the truth about having a miserable day at work.

Another example:

You had a boring weekend and end up at home doing nothing. You lied and end up telling them you went out walking in the park and got home tired or you've visited your distant aunt and are back home to make your day interesting.

Or telling them ''I only got eyes on your and never ever fantasized about anyone else, not even a celebrity'' when in fact you do find other people of the opposite sex attractive. Or you don't feel like sharing about the day got humiliated at school during your childhood years and instead just tell them you've been a quiet kid with few friends, don't add too much details. Or tell ask if they ask how they're in bed, tell them good and just guide them through some more new things even if they did suck.

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Those are obviously still lies but do you really have to be truthful at all times, even in small, insignificant things they'll never find out?
What do you think of trivial or white lies in a relationship?
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