Rian is helping Lorenzo meet certain people. By doing this he gets to stay by his side and hopefully figure out Lorenzo’s motives and what the Umbra Project is. This way, he might be able to save his agency. This is why he’s putting up with being repeatedly raped and continuing to joke with him rather than running away or directly fighting him. His goal is to remain in Lorenzo’s good graces for as long as he can until he gets some useful information. After that he might dip (or try to anyway).
Lorenzo knows all of this, but he’s obsessed with Rian and feels that he can control him regardless.

Tell me, who has the upper hand?
Like I feel like Rian is losing but then he’s having his way too easily…that’s a complicated situationship. They’re not even making their relationship go anywhere…? What are they? Coworker? Sex partners? Spouse?