This seriously happened to a mate of mine. Was living in London and met a great girl. He moved home and she came back a couple of month later. In the interim, my friend spent his days working and his spare time on his wind trainer (stationery bike mount), for up to three hours at a time.
When she came home, he had terrible trouble. To put it bluntly, he couldn't keep it up. She thought he didn't lover her anymore, or there was another woman. He went to the doctor who basically told him he was an idiot, not to ride for that long in a stationary position, and within a couple of weeks, problem solved.
They now have one child and another on the way.
See, happy endings all round!