it's not like he feels anything it's just he has to obey his master for the day but they were interrupted when Taemin made his mind to finally confess argf
He left because he respects Min Woojin as a person. He was asked firmly and politely to leave and Taemin respects Woojin's privacy so he complied.
He was actually worried about what was going to happen with Jiwook and Woojin. So he wasn't entirely "not distressed". But yeah, I mean why wouldn't he feel jealous when Woojin keeps telling him that he was only person that evere mattered to him.
I noticed that when woojin told taemin to go home, taemin wasn't distressed or sad or anything about being sent home. He didn't feel jealous or thrown away. If it was his brother, he would have lost it. Very consistent characters
ilu taemin my love
hope jihoon isn't gonna come fuck up everything :)