Werid position to be in

Hi, So was dating this girl in the office (ik beginners mistake) but that's what happen when you don't think great. It was going great for around 6 - 7 months, since I didn't see a long term future or rather I wasn't confident I decided to break it off. Yes it was quite werid after that, we didn't have much to talk and we had our fights as to why it happened. Cut to present, she sort of misses the affection and time that we spent. We occasionally joke about the time that we had and it's ironic how things turned out to be. Most likely will be leaving the office in a month if things go right and she has asked me about where I am joining but I haven't let her know. There is side of me which wants to let her know what she is missing or will me and she will have to settle for medicority. Then theres the other side which says let it be how it is and move on. Help me decide. P.S: She is a cheater and was cheating on her current relationship, and before anyone comes to me I am guilty as fuck.