[chipotle_coyote]

If one person can promote, demote and fire the other, that's a potentially huge can of worms even when the manager isn't starting the relationship off with casual abuse of power. Maybe some of the other complex thoughts should be like, "Can the manager be trusted not to play favorites with their lover?" and "How will the rest of the team react?" and "If this relationship goes south, can they avoid the appearance--and actuality--of retaliation?" There's a reason a sizable minority of companies have HR policies prohibiting office romances between two people in the same reporting chain, and it's not (solely) because HR professionals are big jerky jerk stick-in-the-muds.