'what would be it' =?

[thedaffodils]

Hello!

Could you please tell me 'what would be it' means in the following context?

Dear Bel,
Throughout my married life, I always said if my husband had an affair that would be it. But when it slaps you in the face, as it did after eight years of marriage, there is a whole picture to consider - most importantly your children.

Source: the Daily Mail

BEL MOONEY: How can I ever trust again after so many lies? | Mail Online

Thank you!

[heidita]

Hi deffodil:)

That is it = end of story

In this case: she would get a divorce, seperate...take a decision about her marriage.

Similar to "that does it". You might know that expression:)

[thedaffodils]

Hello Heidita,

Thank you for your help. Your explanation is good.

Is 'That is it' an idiom? I don't find its definition by Google search or my dictionary.

[heidita]

I think it is not listed as an idiom as "that is it" can mean so many different things.

I would certainly consider it an idiom here.

When you are angry, disappointed, fed up, "that is it" always means, ok, I've had enough!

[thod00]

I wouldn't call it an idiom.

In saying "that would be it", the 'it' refers to divorce. There are many actions that could give rise to this condition. She is 'drawing a line in the sand', now that's an idiom.

[thedaffodils]

Thank you very much for your answers, Heidita and Thod.

[heidita]

drawing a line in the sand...very nice, thod:) thanks.