I wanted to say:
We must not have noticed that Lilia came home last night. I was unsure how to say it, so I didn't
But now that I have had time to think about it, I'm still not totally sure. Are either of these correct?
No nos debemos haber dado cuenta que Lilia volvió a casa anoche.
No nos habremos dado cuenta que Lilia volvió a casa anoche.
The first sentence comes to mind because it is closer to a word-for-word translation, but
I THINK I have seen the second construct to mean "
must not have," but I'm unsure, so any input with explanations is appreciated.