[Because as he said, he's not going to force Kazuma to get along with this man. It's not any of his business who Kazuma befriends and he understands just how complicated their history is. He just doesn't want there to be any more physical confrontations on either side. And really, he considers the topic dealt with for now.]
... So, you met Holmes in that other world, did you?
[He's not asking because Holmes is his best friend, he's asking because of the chronology of it all. Kazuma suffered amnesia before he ever truly got to meet Holmes, and then just after getting his memories back, he was whisked away to another world. This implies that his encounter with Holmes in this other world would have been the first substantial one, and a chaotic one at that.]
no subject
[Because as he said, he's not going to force Kazuma to get along with this man. It's not any of his business who Kazuma befriends and he understands just how complicated their history is. He just doesn't want there to be any more physical confrontations on either side. And really, he considers the topic dealt with for now.]
... So, you met Holmes in that other world, did you?
[He's not asking because Holmes is his best friend, he's asking because of the chronology of it all. Kazuma suffered amnesia before he ever truly got to meet Holmes, and then just after getting his memories back, he was whisked away to another world. This implies that his encounter with Holmes in this other world would have been the first substantial one, and a chaotic one at that.]