While at BTS 3rd Muster Suga, Namjoon, Jungkook, and Taehyung went into the bathroom.
Then Suga heard someone sneeze and sniff. He then said
"Namjoonie?"
And then a reply came
"Yes hyung?"
Then When Taehyung finished he heard a sigh and he then said.
"Jungkookie?"
And a reply came saying
"Yea Hyung?"
( what got me was when they recognised each other and when Suga called Namjoon, Namjoonie and when Taehyung called Jungkook, Jungkookie)
