I broke up with my significant other and then went and spent the night with an old flame and ended up having sex.... a lot. It was amazing and I don't regret it. We'll never be together, and that's fine. We both just needed the release. Now I'm back in the dating scene and casually seeing a couple people. My ex has no idea about either situation and I don't know how to break the news or if I even should.
exactly. what's the issue? the only reason to "break the news" to your ex is actually to "rub his face in it". if it was that kind of messy break-up, go nuts and tell him, but don't convince yourself you're somehow doing it for his benefit.
Why break the news at all? It will only insult your ex (maybe hurt their feelings) and why? If you're exes, it shouldn't matter what you do. Save them the hurt, and yourself any negativity they may have to offer you about it