In switch-reference (SR) constructions in Cupeño, if two subjects are in a part-whole relation, same-subject (SS) marking is obligatory and different-subject (DS) marking is ungrammatical. The possessed subject in such constructions is a body part that idiomatically expresses emotions when combined with certain verbs. Speakers have a choice in using SS- or DS-suffixes in these contexts. The overt expression of possession is required.
Hill, Jane H. 2005. A grammar of Cupeño. Berkeley: University of California Publications.
Hill, Jane H. 2016. Takic switch-reference in Uto-Aztecan perspective, in Rik van Gijn & Jeremy Hammond (eds), Switch reference 2.0, 115-152. Amsterdam: John Benjamins.