[Daydreamer]

For me, I would say date for two years, move in together for at least a year, and then at least a year of engagement. So living together for two years in all one of which you are engaged. That way you'd be together for about for years before you tie the knot. Although the engagement could be shorter. It depends on the person, but that's how I think I would want my relationship to go. As to sex, I know I wouldn't be comfortable marrying someone I hadn't slept with, but again it's different for every person.