People in close relationships often need to sacrifice their own preferences and goals for the partner or the relationship. But what are the consequences of such sacrifices for relationship partners? In this work we provide a systematic investigation of the consequences of sacrifice in romantic relationships, both for the person who gives up their goals as well as for the recipient of these benefits. In 5 studies combining experience sampling and experimental methods, we examined whether performing and receiving sacrifices is linked to the experience of ambivalence, that is, mixed feelings toward a partner. In the last 3 studies, we also examined the specific positive and negative reactions associated with sacrifice. Results revealed that performing and receiving sacrifices are both linked to ambivalence toward a romantic partner. Recipients of sacrifices experienced higher negative mood, guilt, and feelings of indebtedness, but these were accompanied by higher positive mood, gratitude, and feeling appreciated by the partner. Sacrificers mostly experienced negative reactions, such as higher negative mood, frustration, and feelings of exploitation, but they also reported some positive reactions, such as feeling happy from benefitting their partner, proud of themselves for being a good partner, and had increased expectations that their partner would reciprocate the sacrifice in the future. In sum, this work provides the first comprehensive study of the emotional reactions that are triggered by sacrifice and shows that sacrifice is a double-edged sword with both positive and negative consequences. Implications for sacrifice and ambivalence are discussed.