Gustave has taken it upon himself to observe Marion and Sanglain following the death of the Princess and DT.   But KT thinks Gustave is in the city of Marquesas for other reasons. 
Gustave, you should try 
to control your habit
Gustave, deberías tratar 
de controlar tu hábito
Gustave, deberías tratar 
de controlar tu hábito
Gustave, você deveria
tentar controlar esse