Why is she now your ex? I think it depends on what happened to make your relationship friends not lovers.

flirt and see how she reacts. if she responds (in a good way), keep it up. if she doesn't, then continue being friends. edit: "that you would treat her right" did you cheat on her? if she's still talking to you after you cheated on her, then, she'll get back with you.

You say that you were too jealous. There's several things excessive jealousy indicates to a girl. First, overly jealous people give the impression that the other person could do better, why else would you try to keep other possible mates away from them? And jealousy is men is something women want in moderation. Anything that seems the slightest bit scary is a red flag for us. He doesn't like the men I work with, so will he forbid me from having drinks after work? Will he say I shouldn't work at all? Will he emotionally or physically attack me? This may seem like overreacting, but most women can't help but analyze a guy in the long term, and being jealous when we think he shouldn't marks you as potentially a poor choice. Awesome that you've learned to control your anger, but have you given any thought to seeing a therapist or getting formal counseling? Dealing with the roots of your problem would not only strengthen you in dealing with it (and you seem like a strong individual already) but help you rid yourself of it. If you two are friends, she'll support your efforts and respect you for it. Even if she never comes around, she may be a little jealous herself of the next girl. As for your actual question, I'd hold off except for when the situation is perfect for an offhand comment you know she'll like. Watch the movie The Tao of Steve, and be desireless.