Reward Kiss - S1.E18

It turns out the kids already know how to swim and they go on ahead, but Treize cannot. Lillia throws him in the water and spurs him on to shore, but he ends up having to be saved by Lillia who performs CPR, saving his life. It is revealed that Carlo is in fact a girl, but only Treize knows this; in return, he tells her that he is a prince, but does not reveal the country. Travas tells Treize that the whole plan to shoot down the seaplane was planned by Mr. Morceau, who was actually a secret operative in the army before being cut loose. Treize ends up going back to Ikstova by himself, and Lillia learns how all this time she has been jealous of how Treize can do many things she cannot.