Why do you say this guy is untrustworthy? He may be, but it does not seem that he has betrayed your trust so far.Did he promise to call, and then not do so? From your post, it doesn't seem like any agreement was reached about future contact. Speaking to someone once does not create an obligation to continue talking. Having a phone call with someone is a way to gauge possible comparability (or lack thereof). If the phone call ends in "bye," it is usually a polite way of indicating there will be no future contact. No obligation is created or explanation owed if someone decides there is no connection after only a couple of message or calls. They just don't reach out again. If you expect everyone you contact to continue calling/texting indefinitely, you will only be disappointed. Have you ever contacted someone, and then decided that you were not interested (for whatever reason)? It's just a part of the dating process. Most people are not going to be compatible, so they move on. It's more of a marathon than a sprint to find someone who really is a good fit. I know you only talk to one person at a time, but most people talk to several at once. If they had to explain why they didn't want to continue talking to each person, it would be a full time job. That's why most people just stop reaching out once they decide they aren't interested.