Do people know when they are seen as pressing too hard, yielding too readily, or having the right touch? And does awareness matter? We examined these questions in four studies. Study 1 used dyadic negotiations to reveal a modest link between targets’ self-views and counterparts’ views of targets’ assertiveness, showing that those seen as under- and over-assertive were likely to see themselves as appropriately assertive. Surprisingly, many people seen as appropriately assertive by counterparts mistakenly thought they were seen as having been over-assertive, a novel effect we call the line crossing illusion. We speculated that counterparts’ orchestrated displays of discomfort might be partly responsible—behaviors we termed strategic umbrage. Study 2 revealed evidence for widespread strategic umbrage in real-world negotiations and Study 3 linked these behaviors to the line crossing illusion in a controlled negotiation. Study 4 showed that this illusion predicted outcomes in a multi-round negotiation.