The Guardian does a very intelligent piece about a completely happy asexual couple.
This is my favorite paragraph:
"People always ask how our marriage is different from just being friends, but I think a lot of relationships are about that - being friends. We have built on our friendship, rather than scrapping it and moving on somewhere else. The obvious way we differ is that we don't have sex, though we do kiss and cuddle. We like to joke that the longer we're married the less unusual this is. By the time we've been married five years we'll be just like everyone else."