You say that the proof is there, But where does Lena say in the game that she's being blackmailed by Robert? Never mind say it, where does she even hint it? After all she's the person you're claiming Robert is attempting to blackmail. Wouldn't she be making a big deal about that? Somewhere?
Lena is an intelligent girl. Much more intelligent than Robert is. There's no way he could do that, without her realising it?
Now we may have gone all around the houses, discussing all the hypothetical reasoning behind your belief that Robert is a scumbag, because he effectively blackmails Lena, or at least attempts to, to get her on a date and hopefully into bed. But what it all boils down to, is where is the real evidence? When does Lena say that he was blackmailing her, to take advantage of her, as you claim? Where does she even give the briefest indication, that that's what she believed Robert was doing?