"When one is enough"

A heartbreaking story from the New York Times:

When we saw the specialist, we found out that I was carrying identical twins and a stand alone. My doctors thought the stand alone was three days older. There was something psychologically comforting about that, since I wanted to have just one. Before the procedure, I was focused on relaxing. But Peter was staring at the sonogram screen thinking: Oh, my gosh, there are three heartbeats. I can't believe we're about to make two disappear. The doctor came in, and then Peter was asked to leave. I said, ''Can Peter stay?'' The doctor said no. I know Peter was offended by that.