Social context shapes negotiators’ actions, including their willingness to act unethically. We use a simulated negotiation to test how three dimensions of social context—dyadic gender composition, negotiation strategy, and trust—interact to influence one micro-ethical decision, the use of deception. Deception in all-male dyads was relatively unaffected by trust or the other negotiator’s strategy. In mixed-sex dyads, negotiators consistently increased their use of deception when three forms of trust were low and opponents used an accommodating strategy. However, in all-female dyads, negotiators appeared to use multiple and shifting reference points in deciding when to deceive the other party. In these dyads, the use of deception increased when a competitive strategy combined with low benevolence-based trust or an accommodating strategy combined with high identity-based trust. Deception in all-female dyads decreased when a competitive strategy was used in the context of low deterrence-based trust.