What do you think...

The song that was played 45 years ago and at the anniversary dinner was Smoke Gets in Your Eyes. He sang the words to her as they danced. The first half of the song sounds like a love song to her but the second half of the song makes clear he lost his love - the woman who died. She never heard those words before in this context and realizes what the words mean.

They asked me how I knew
My true love was true
I of course replied
Something here inside
Can not be denied

They, said some day you'll find
All who love are blind
When you heart's on fire
You must realize
Smoke gets in your eyes

So I chaffed them, and I gaily laughed
To think they would doubt our love
And yet today, my love has gone away
I am without my love

Now laughing friends deride
Tears I cannot hide
So I smile and say
When a lovely flame dies
Smoke gets in your eyes

Smoke gets in your eyes

She very obviously no longer feels like she did before the revelation. This news about her husband's past has shaken her resolve and her live for her husband. Their relationship will never be the same.

They're too old to divorce and too established in their home, I mean where would each one go? They have no children to move in with so my guess is they'd just go on as before, but with subtle changes, she being more closed in. Some dialogue hints at their future together after a heated discussion about Katya's perfume in the air and her "ghost" hanging around:

"And then we're going to have dinner,
and then we're going to go to bed.
And then we're going to get up.
And we'll try and start again."

OK, Kate, I can do that.
We can do that.
I promise.