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.
Where are you going? We're still in homeroom!
إلى أين تذهبين؟ لا تزالُ الحصّة الحرّة منعقِدة
Wohin gehst du?
Wir haben noch Unterricht!
¡Oye, tú! ¿Adónde vas?
Hé, où est-ce que tu vas ?
Dove stai andando?
 L'ora non è ancora finita!
Ei, aonde vai? Ainda tem aula!