Booty Call

Booty Calls occur in The Ballad of Gay Tony after you impress a girl at Maisonette 9, and you've had your time in the bathroom. She will give you her number and tell you to call her. You can call her, or she will sometimes call you. After the call has been made, the girls house will appear as a pair of buttocks on your mini-map. Go to this location and listen to the rest.