Gregory says they encourage family discussion about their situation. "I bring up the subject maybe once every three months to remind them that it is legitimate to talk about," he says. "But the children live it as naturally as they breathe oxygen. Sometimes Luke will even suggest: 'Look, you might ask me what it's like to breathe the air on a different planet, but I don't live on a different planet. I live here, I breathe oxygen, and you are my dads."