the best way is to probably just talk to him or her and show them your true feelings.
to let him know that you are alone you shouldn't talk about other guys around and if he brings up something then be like i was hangin out with this guy or something to show your not hanging out with people just not dating.
you let her or the law handle it. dont say anything to them cause that will only escalate the situation.
Oh, please don't let my ex know that because it isn't true. Now if you are talking about your ex, you should just let them know how you feel.
I don't know that you should necessarily believe "every single thing" that any one says, let alone an ex.
Sure why not. Sure why not.
When your date wants to date your enemy, depending on how you feel about the ex, then you let them. If you love your ex, your enemy can be a...well you know, then don't let them be together.
If really want to let your ex know you still love them, start asking them to hang out with you and some friends. The more you hang out, the smaller the groups get, until you start asking them out to the movies or dinner. If they let you do that, then they will know, and they most likely like you too.
Sometimes it is better to let an ex to know how you feel. You never know, they may feel the same way.
Talk with her and explain to her how you feel from there she will let you know where she stands - then you will know if you can begin dating again or let go and move on.
it launches a meteor at you
If you still have feelings for your ex then let him/her know that, then you both decide if you still have a chance togther.
Talk to her about it and let her know she has to stay away from her ex.