Unfortunately, they wrote Sila too transparent with his feelings regarding Kwan and Minta, that having him sleep with Kwan isn't true to Sila. I think, had they let him lead Kwan on and is a bit neutral towards her then yes, that would make sense. But he isn't...he doesn't like her and it shows. And he loves Minta, that also shows. So his feelings are too open and out there to having him sleep with Kwan even if for revenge. But Bie you can see why he did it and he was playing her and seemed to like it half the time. Sila in here looks like he wanted to cry and just doesn't like her...period.