Trust is the upmost key for a successful relationship

So many why?
So many thought.
Why is it that when couples doesn't get to quarrel or have arguement suspicious thought comes to our mind? Many why comes to our mind?
We tend to think they are lapses (cheating) in our relationship, doubt begins to cloud our sense of humor.
Most especially ladies, comment and share ideas why we ladies react when guys don't get to have arguement with us.