Not exactly as the title says, but say you date a girl for 4 years, live with her for a year, everything is good. You then buy a house together, and its like she literally matures 20 years in the space of 6 months (personality wise), suddenly has plans to settle down and make a family, completely dismissing any exciting plans you made together to enjoy whilst still young. Sex becomes almost a gift from her and not passion, and conversation is either about work/kids/house. What would you do. This is coming from a 27 year old.