It was just a mask. Beware, as if you both go back to your old ways of arguing and dealing with problems, you'll get back to where you were – apart. Don't let that happen. Don't get lazy and don't take things for granted. The first few weeks of being together again as also the first few weeks where he's most likely to “run for his life” and leave you or just decide that you shouldn't have gotten back together in the first place.
For example:- Things were all OK before. One day you ended up talking to your ex in a casual manner. You did not have anything in mind which was bad. It was a casual conversation let it be a text or a call. Let it be after many years or months. From that day your partner started behaving weirdly. Even after telling you everything was fine. In this situation, your partner acted in a way where everything seems to be fine. But that was not the case. He/she felt bad when you talked to your Ex and trust issues built up. So try to get deep into the problem of What Went Wrong. Some things might be right from your side but not your partner's side.
Relationships cannot survive on love. Trust is the foundation upon which all relationships are built. If you break trust with your partner, the relationship suffers. In order to rebuild trust you have to repair the hurt you inflicted on your mate. In my work with couples, I guide them through a 5 step process to repair hurt. For easy remembering the steps begin with the letter A.
Understand the breakup. What did each of you do to contribute to the breakup? Most relationship troubles do not crop up unexpectedly, but build up over time. The odds are good that it wasn't a one-sided problem and that there were signs that it was coming. Take some time and do some soul searching before you attempt to get your ex back. You want to make sure you are not wasting your time or energy on something futile.
You may worry about the old adage, “Out of sight, out of mind,” and use that as a justification to reach out. The thought of him moving on and forgetting about you is too terrifying to bear. One little text won’t hurt, you reason. But, in this instance, it will hurt. If you want your ex back, it is important that you strictly adhere to the no contact rule.