Trust is an essential part of any successful relationship. It is the foundation of a happy relationship, says TwoOfUs.org in "Why Trust Matters." Without trust, your relationship will ultimately fail. Trust takes time to build, but it's worth the time and effort. As you grow in your relationship, there are certain signs that you can watch for that point to your boyfriend's trustworthiness.

He Has Integrity

An honest man's words and actions will be consistent, says Charles D. Schmitz, who earned a Ph.D. from the University of Missouri-Columbia and Elizabeth A. Schmitz, who earned a Ed.D. from the University of Missouri-Columbia and are co-authors of "Is Your Man Someone You Can Trust?" For example, if your boyfriend tells you he will be faithful to you, his actions will also show that he is faithful to you. Having integrity is an essential component of being able to trust your boyfriend. Your boyfriend should honor his word and keep his promises. If he says he will call you at a certain time, he will. If he tells you he will attend your cousin's wedding with you, he should.

He is Honest With You

Your boyfriend should be honest and open with you at all times. For example, if he wants to catch up with an ex-girlfriend who will be in town, he should discuss it with you. If you are uncomfortable with the situation, he should respect how you feel, even if he disagrees with you. You should be able to believe what he says without questioning him. You shouldn't be tempted to snoop through his belongings or check on his whereabouts. If he makes a mistake, he should admit it and apologize.

He is There for You

You should know that if you need anything, he will be there for you. For example, if you have a bad day at work, he will be there to comfort and reassure you. If your car breaks down, you know you can count on him to pick you up. Your boyfriend should have your best interests at heart and make your relationship a priority. Trust develops when someone demonstrates behavior in which they give up something for the health of the relationship, says TwoOfUs.org in "Why Trust Matters." You can tell him things in confidence and trust that he won't share it with anyone else. He should listen to you with interest when you talk.

Take a Look at Yourself

One thing that affects trustworthiness is your own readiness to trust, says Forbes website in "How Can You Know Whom to Trust." The way you respond and approach someone can affect trust. If you are always expecting the worst from your boyfriend, he may meet your suspicions. If you accuse him of things he did not do, it can affect how he reacts to you. However, most people respond in a positive way to those who show they trust them, according to Forbes.