While taking their usual bath, the boys discuss how much Kyotaro is like an old man. The next day, when they go to school, they find themselves exhausted by climbing up the stairs... and learn that they're all becoming old men!
You're just going to throw that out there? 
"Come to the bath"?
هل تلقي هذا الكلام بهذا الشّكل العابر؟
رافقنا إلى الحمّام"؟"
Was heißt hier, mit dir baden gehen?
¿Vas a invitarme como si no importara?
¿Vas a invitarme como si no importara?
Comment ça,
aller aux bains ensemble ?
Te ne esci con "Vieni a fare il bagno con noi"
come se niente fosse?
Você vai apenas soltar essa?
"Venha tomar um banho"?
«Пойдём искупаемся»? И это всё?