This paper critically assesses the widespread claim that jealousy is a response to infidelity. According to this claim, herewith called the entitlement theory, jealousy is only an appropriate response to a relationship between a loved one and a rival if, by entertaining this relationship, the loved one does not treat the jealous person the way she is entitled to be treated. I reconstruct different versions of ET, each of them providing a different answer to the question why we should assume (...) that jealousy is a response to infidelity. I show that even the most plausible versions enjoy less argumentative support than it seems at first sight. The positive aim of this paper is to present a more inclusive account of jealousy as an alternative to ET. According to this account, jealousy serves to disturb the rival relationship and to gain the attention and affection of the loved person. Jealousy so understood is not only an appropriate response to infidelity but has wider appropriateness conditions. However, it plays a role in the negotiation of norms concerning exclusivity in personal relationships. The inclusive account does justice to the continuity and commonalities between adult and infant protest against rival relationships. (shrink)