Who are you trying to justify it to hun? Me or yourself?
Theres a couple of scenarios in this situation - you either do it and its a giant mistake and you end up back where you started, do it and it works out great and you get back together, do it and its good once and nothing changes but you have a good time (DOUBTFUL), don't do it and everything stays the same, don't do it and regret it for the rest of your life. Which one do you want, and which one do you think would happen?