I think a healthy dose of communication to resolve this matter is the best course of action. Silence and separation only amplifies emotions that are already raw. Explain you want to move on and apologize for not addressing it directly sooner. Walking away is never a respectful dissolution if you had a established relationship. Once you have paid that respect forward, its up to them to accept that information and move on. But I do believe the ball is in your court to acknowledge (through words) that this bond has ended.