"You genuinely believe the Lestranges were responsible for her behaviour? Bellatrix isn't some doe-eyed girl who simply got led astray, you know." He shook his head, before holding up his hands "Though I shall not argue with you, Severus, your business is your own. I just hope you know what you're doing." Severus was beginning to sound like Narcissa. She too believed Bellatrix was capable of change, or even normal human emotions. Though that was different, they were bound by blood, plus Narcissa didn't bare witness to Bellatrix's chilling ruthlessness during the war.
Changing the subject was the safest bet. He didn't want to fall out over Bellatrix, partly because she'd find it terribly amusing. "So aside from acting as a snake charmer to all our fellow Slytherins, and - of course - aside from your glorious acting début," he paused to smirk, "what else is going on, if anything?"