how was the relationship between desdemona and othello particularly vulnerable to being wrought by a villain like iago

Young love between two people who don't know each other very well is always vulnerable. They haven't been together long enough for one or the other to say..... "She/ he would never do that." They don't have the time to understand the other's minds, thoughts, or feelings. Unforotunately, Othello did have the foresight to simply ask his wife, and she didn't know him well enough to question what was wrong.