Gwyneth Paltrow and Chris Martin consciously uncoupled. How do you announce a break up?

I was at a function many summers ago when a friend’s dad asked me several questions about my boyfriend. Five minutes into the conversation I realized that he was asking about my college partner that I hadn’t been with for years. He thought we were still together; I was answering questions based on my current relationship (two different conversations were happening at the same time). It was awkward. I had to stop and say, “I am sorry, are you talking about ____? We are not together anymore.” He looked shocked and genuinely disappointed. And I had to spend my evening justifying my break up to a stranger.