Félix: “I’m sorry…”

Apparently, Félix is going betray Ladybug. But what interest me the most is that he says “I’m sorry”, when he is about to betray her. And just look at his face! It’s seems like Félix didn’t want to betray Ladybug? But what is his motivation? Why did he do it, when he clearly doesn’t want to?

Edit: In the picture, nobody is around Félix when he is apologizing. Nobody seems to notice him. There is no need for him to act like Adrien here, because nobody is around him or even noticing him. So his apology does seems sincere I think?