Make Lance masturbate twice to lower his purity to around 80%. Then go to a bar every day. When his purity is around 65%, go to a prostitute. Then it will be around 55%. At this time, make Lance's arousal around 80% and have him rape the bandit. Here's a tip: Before raping the bandit, if you make curse attunment and Lance's arousal around 80% (there shouldn't be even a slight difference between the two numbers), next day Lance will forcefully masturbate the protagonist and even ejaculate. If curse attunment and Lance's arousal don't match, he will masturbate but not ejaculate. It seems to be a code problem.