"Oh you're his brother," Klaus said delighted, "Now the flirting makes sense." It was a tease mostly, Sirius was cute, as was Regulus in his own way. It sounded a little like they'd had the sort of early life that he and his siblings had, under the roof of a parent who simply did not understand children and demanded things be done in a certain way. Klaus could relate.
He nodded, "Yes, it's the only thing that saved my siblings," He agreed, well all of them but Luther, he hadn't really made it out unscathed. But the rest of them, they'd gotten out, lived their own lives away from the toxic place they'd grown up. Sure Klaus chose his own level of toxicity outside of the Academy, but that was his choice and that's why it was okay.
"It helps," He said when Regulus laid back still listening to the music, with his hand free Klaus rummaged through his piles and found a bag of chips he didn't recognize, it was like the door took him home without it actually being home, it was fascinating. He opened the bag and tried one and then decided he liked them so he offered some to Regulus as well.