How to do the threesome with vance?
- Do the Mystery At Work quest
- Have Ring of Compulsion level 3 (from Homewrecker quest) & have its use available for the day
- Attend the afterwork party (from A Taste of Sugar quest)
- Choose "Defuse the situation and lead Vance into your scheme"
- After arriving at the boss' home, you'll be given the option for threesome