Did Christian know Francois' secret?
I got the impression that he did. Recall that Francois got completely smashed at a gay bar in Cape Town and called Christian to pick him up. I sensed that Francois was in a gay district of the city and that Christian was familiar with that area, probably because he had partied there before with friends. That's not to suggest that Christian was gay or bisexual at all. He was demonstrative with his friends, even male ones, so it would be consistent with his characater that he would party with gay or straight friends and think nothing of it.
I found it peculiar that Christian went to Francois' hotel room and hung around. If the purpose was simply to make sure Francois got home, why not leave right away. Instead, he goes to the bathroom, has a drink, smokes a cigarette and sits on the bed with Francois. So what is going on there, I asked myself? Had Francois admitted his attraction to men, and specifically to Christian? Was Christian aware of it and using it to get money from Francois? Recall when Francois leaned in to kiss Christian and Christian leaned away, but did not get up or try to leave. Why not? Was something supposed to happen, and Francois took it father than was agreed?
Movies like this are so enigmatic becuase they leave so many details to your imagination.