I was keeping a promise to their son.
My brother Rhys was twenty-two when he got his diagnosis.
He kept it from our parents for eight months. I was the only person on this earth who knew, and I only knew because I found a hospital letter in the door pocket of his car when I borrowed it in the February.
He made me swear in a car park outside a garden centre.
I was eighteen. I swore because he asked me to, and because he was crying, and because I did not have the faintest idea what I was agreeing to.
The reason he would not tell them is the part that people find hardest, and it is not complicated at all when you have met my father.
Our father does not have bad news. He has problems, and problems have solutions, and a man who cannot produce a solution has not tried.
Rhys had watched him do it to a cousin in 2013 and to his own brother in 2016.