I think that happens when they love you, in enemies the bandits must love you 78, then the morale of the camp must be less than 25 then you will have the opportunity to meet a bandit on the way and he will give you those options
I've tried, but even with reputation 100 and morale 0 it doesn't trigger. Are you sure the event is after fighting Scar and not after? (I've submitted to him).
Edit: at the end you need to be homosexual, thanks for your help!
