It's Pussycats, and the coworker is named Masha. I haven't played in a while, so I don't know if you still can do it.
IIRC you had to work there, and wait until a coworker made some sort of mistake. The boss wanted to punish her, and with high dominance you could turn it into a threesome, and get her number afterwards. Then, either right away or after calling her on dates until you had enough relationship, she told you that she lived in the basement of the sex shop in the Red Quarter, and you could find her there on evenings. You can do various types of BDSM stuff with her: pet play, candle play, sex.
The assets are still there as of version 0.8.4.