What can you do about parents? It doesn't matter if they live on the other side of the city or the country or the world, they're going to do ridiculous things. I happen to live far away from my folks, so it's hard for me to stop them from doing things like crafting a bizarre voodoo shrine to professional bicycling.
Now don't get me wrong, I happen to really like the Tour de France. When I was young I went through a stage that lasted several years where I would wear European style bicycle caps with the brim flipped up. I wore them everywhere. I have distinct memories of being harassed by larger children at the YMCA summer camp because of my flipped brim hat. Looking back, I totally understand. What 12 year old could the resist the urge to the knock a stupid looking hat off a smaller kid's head? But I think I got off topic here.
The point is, we're talking about educated professionals here. Two people who lead normal lives have built a sacred place of worship in their living room dedicated to a bicycle race held on the other side of the world. What can you do?