Galko's skin got really dark as a result of tanning.
Otako comments that since Galko's skin has tanned so much, her nipples must be dark as well. Along with Ojou, Otako yells that Galko has dark nipples.
People can like whatever they want.
للناس حرية اختيار ما يروقهم
Kann doch jeder mögen, was er will.
Qué tiene de malo.
Et alors ? À chacun ses goûts.
Ognuno ha i suoi gusti, no?
O que tem? Cada um faz 
o que bem entender.