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. 
No wonder they always pull one 
over you in the cabarets.
Por eso no me sorprende que 
te engañen en los cabaretes.
Si es que no me extraña que te engañen en todos los burdeles.
Não me admira que sempre
te passem para trás nos cabarés.