One of my favourites is when Roman returns from his brush with captivity. I’ve assumed it’s improvised (brilliantly), but it sums them up entirely - Roman seeking connection to his siblings, both incapable of it, and then Logan’s arrival ruining the bonhomie :
Roman: I did think... when I thought, you know, they were gonna... vacuum out my innards and fill me with concrete or something... Look, if we come through this... is there a thing where we like... talk to each other about stuff... normally?
Shiv: ( In silly voice ) You wanna talk to each other normally?
Roman: Okay.
Kendall: ( In silly voice ) You mean... talk about the big sh¡t?
Roman: Okay.
Shiv: Yeah, we can talk about the big sh¡t.
Kendall: We can talk about... our feelings. ( Laughter )
Roman: How am I the mature one here?
Shiv: We don't have any feelings, what are you talking about? ( Laughs ) Who is this helping?
(Logan’s Helicopter whirs ) ( Shiv laughs ) Okay. Emotional gunship incoming. Yeah, send out the distress signal. We're under attack.