Hey SG.... yeah, I disagree with dating because it brings an innocent bystander into the situation. No matter what you tell them, it just isn't fair to them, or to you, in my opinion. I really don't think you should date unless you really are done with your M. Then, I have no problem with it.
DBing isn't about manipulating, it is about change. Change in you first!
Kara, being upbeat in his presence would be good. Especially if it's zipping past him on the way out the door! Picture it... you looking good, smelling good, smiling... out the door with "I'm not sure when I'll be back!" And the door closes before he can open his mouth. And then you don't answer the phone. That's going to make his head spin, while you enjoy a good book and a hot chocolate!