Read full articleCosmopolitan53 Things You Should Never Do in a Healthy RelationshipCosmopolitanSeptember 7, 2017 at 12:00 AMLink Copied1 / 5453 Things You Should Never Do in a Healthy RelationshipRelationship experts share the worst mistakes they see couples make — and how to avoid them.GettyRelationship experts share the worst mistakes they see couples make — and how to avoid them.From Cosmopolitan View comments