I think mahae is something fans really enjoy and haechan likes to service fans by being vocal about his exchanges with mark. Mark also gives great reactions so it’s a fun dynamic to show fans. Dongren have a shit ton of interactions lol what r you talkin about!! During fanmeetings and showcases, in official content, and behind cams ! But you’re right that it’s not always “flirting.” It’s subtle, like a sensitivity towards each other, renjun saying something that’s really only to riff off something haechan said, hc sharing a joke that’s only really meant for rj, tension, Haechan not being able to look at Renjun doing sit-ups in the eye but being perfectly able to ogle the other guys, etc