I am riding about 100 miles a week on my roadie at the moment, but am trying to find something fun to do with my wife. She has expressed some interest in riding, but that kind of riding would be 10mph to Starbucks and back with maybe a lap around the park. I have an opportunity to get a fixie at a great price and was thinking that if I was learning to ride the fixie, it would make the rides with the wife more interesting. She would be on some sort of MTB or hybrid if that matters...

Good enough reason to get the bike?