It's interesting that you mention that one, because that is exactly what people sometimes do. You will find that very needy or jealous people frequently get easily concerned and obsessive about every little detail, worried that their partner may leave or lose interest. They get paranoid, they spy, etc. They make the situation worse, push the person away faster with their behavior, and create a self-fulfilling prophecy outcome.
You might risk spying on your significant other (to make sure they're going to stay your SO), if your life depended - in part or entirely - on them staying your significant other. In relationships that's going to rarely be the case of course. Although consider a case of total financial dependency in a relationship.
Israel is the very needy, dependent partner in the relationship, clearly. Without the US, they would not have survived.
I mean, lots of people do exactly that. It ain't healthy to do, but they do it anyway.
But in general the US doesn't really care if Israel spies on it, and Israel doesn't care when the US does.
All countries spy on each other, and all countries know it. There's a tacit agreement to make some noise when it goes public, but otherwise move on and not care.