Yeah...we tend to trust our spouses. The first time around, at least.
I wonder if people who got divorced because of their spouses infidelity, ever learn to trust their next spouse with the same "innocence" they had for their first spouse.
There's a Jewish saying that the altar weeps when divorce happens among a couple who were both in their first marriage. There's something "special" about the first marriage. I imagine trust is part of that.
