Female capuchins engage in “flirting” behaviors (proceptive behaviors) around around estrus (proceptivity). Typically these include making eye contact with a male, specific facial expressions (I’ve read utt described as “duck face” but the expressions I’ve seen most frequently I would describe as “creepy smiles”), twirling, run back and forth, and then turning to make eye contact again, and a rather shrill vocalization. Sometimes in that process, they quickly touch or grab the male, and then and run a slight distance away, and continue this repertoire. I like to call this the capuchin flirtation dance.
Primatologists (Falotico and Ottoni) studying tufted capuchins in Brazil observed some new flirtation behaviors: female throwing stones to get male attention. They hypothesize that this behavior may be spread by social learning.
Here is the link to the original paper: