See, the problem with Angel/Angelus being two extremes of a binary personality is that Angel is never held accountable (or at least, not by Buffy) for the things he does as Angelus. We never see him apologise: not for the way he treats her while evil, not for Miss Calendar’s death, none of it. Despite the fact that Angel’s whole redemptive arc is predicated on actively atoning for his vampire crimes, he still behaves as though it was all beyond his control. He doesn’t apologise for what he does to Buffy, because he’s not the one who did it – yet even if we consider that to be technically true, it still seems reasonable to expect him to seek forgiveness. Parker, however, has no such excuse: he’s a classic user, a weasel who avoids responsibility for his actions by claiming his motives were always obvious – that Buffy, or whichever girl he’s left broken-hearted, has simply misunderstood him. And then there’s Riley, whose response to being caught cheating is to issue an unbelievably selfish ultimatum: either Buffy can decide immediately that she still wants him around, in which case he’ll make an effort to earn back her trust, or she can stay angry and lose him forever. The speech that Xander gives Buffy at this point to convince her that Riley ought to stay is infuriating. He’s 1% right, in the sense that fairness doesn’t enter into it – Riley has given her an ultimatum, and as sucky as that is, she can’t abstain from making a decision – but given how incredibly shitty a thing Riley’s done by putting her in that position, he really doesn’t deserve Xander’s understanding; he certainly doesn’t deserve Buffy’s. And despite his denials, it’s clear his real issue with Buffy is her greater strength: she didn’t need his protection, he felt insecure as a result, and when presented with an easy out – flying away to the Amazon if his demands weren’t met, instead of staying to make things right – he takes it.