"Happily married? Join our dating site and find yourself someone to cheat with!" [Details inside]?

When I heard this ad the first time on television, I thought Aww, isn’t that a sweet one, a dating site for people who lost their SO or whose first, big love has woefully ended, but I was wrong.
SecondLoveDotNL is aimed at people who have a happy relationship but feel the need to [fill in your favorite euphemism for cheating here].
It is not a swingers site, it is specifically talking about breaking the rut of your relationship and, basically, fuck around, without your SO knowing.
What is your opinion on the existence of such service?
I can’t really put it in good words I am afraid, but doesn’t this look like this is a first (?) step into making cheating ‘just’ okay?