There’s a stigma around bisexuals, that they are promiscuous. I did not tell my ex that I was bi at all, because she and I were exclusive the whole time we were together. It was years after our divorce that I came out as trans.

I was so worried that she would have rejected me if she knew that about me. I was happy with our life we had together, and I never strayed, so why should I have to disclose that if I don’t want to?

If your partner not being 100% hetero is a dealbreaker for someone they should maybe ask about it before marriage? Although in this case it wouldn’t have helped, since the sender says her husband says he didn’t know until then (while calling him a liar). Sometimes people don’t understand their sexuality until later in life, I dunno what to tell you.

I don't understand what difference there is for the wife, someone please explain to me why she(or anyone!) would care about her husband being bisexual vs hetero.

I don't really understand what the difference there would be a spouse, if their other half is het or bi. What should matter is that they chose you