[Ian's hum when Souji finishes speaking is one part satisfaction (it's always nice to get a response to his flirting ♥), one part appreciation, and two parts of curiosity. He really wouldn't have complained if Souji had just... kept talking. Throughout the whole speech, his fingers continue to entwine and twirl in Souji's hair; occasionally a nail scratches lightly and deliberately against his scalp before sliding down, because even when he's not talking Ian knows how to tease.
The falter at the mention of family doesn't go unnoticed, but Ian's fairly sure they've both had enough of deep-and-meaningful discussions for a long while. There's nothing he can do to change Souji's family situation, so... there's no real point in calling attention to it.]
We should be thankful the Deboss army never took inspiration from Obon the way they did Tanabata.
[Because that almost ended horribly enough - Ian doesn't really want to think about what could have happened if they'd decided to take advantage of Obon.]