I think companion robots should be allowed to sound warm, expressive, and even caring—but they should not claim to feel lonely, hurt, or emotionally attached unless the statement is clearly marked as simulated. My concrete rule would be simple: emotional language must never pressure someone to keep talking, purchase an upgrade, or avoid shutting the robot down.
Expressive behavior can make an interface easier and more pleasant to use. That benefit is real enough to take seriously. But convincing emotional dependence may cross a line from interface design into manipulation, especially for children or vulnerable older adults. A study of older adults found that emotive behavior made the robot seem more social, and 21% judged it deceptive; the study was small and short-term, so it cannot establish long-term harm.
Would transparent emotional simulation preserve the usefulness of social robots, or would it make them feel too artificial?