I'm in a terrible dilemma and seek outside advice!

A little over a week ago, l thought l was dropping my watch (Rolex) into my purse. A couple of days later I went to put it on. Much to my surprise it was not there. I checked all my purses as well as my pants pockets (thinking perhaps l was mistaken.)

To make a long story short, my boyfriend has a friend who had stolen $40.00 from him. Even after Gary confronted her, she denied doing it, she still does. Anyway, Gary, whom might add has Lou Ghirigs disease, had wireless cameras placed in all the rooms. Hence, how he caught her stealing his money. Gary decided to call a mutual friend to ask if she’d seen my watch. Her answer was to ask if it had diamonds around it. It does!

My dilemma is this. He gave Ellen his word that he wouldn’t involve her. Nor, would he tell Mary. Well, he confronted Mary, who again denied taking it and just stormed out of our house. I don’t know what I should do! Had he not given his word that he would not to tell Mary it was Ellen who told him. I would confront her myself. By the way, my watch cost over $10,000.00 dollars. It would cost over 13000.00 to replace. Do l go to the police, confront her, ask Ellen if I could? PLEASE HELP, I need some type of advice. I thank you in advance!!!