To be entirely fair, if Severus had a need to discuss murder, Lucius would be the first person he would contact. However, it's not on the menu today. Lucius may consider himself a lost cause, but Severus has that additional footnote to his life: rehabilitated inmate. Murder is distasteful save in rare circumstances. What waits for Lucius at the table is a bottle of wine that has been opened only long enough for Severus to pour himself a glass.

As for the man himself, his clothing is unchanged in style from their last encounter. He's dressed like a Muggle - perhaps a bit anachronistically and very buttoned-up, but a Muggle all the same. Clothing doesn't make the wizard.

When Lucius approaches, he stands and even goes so far as to hold out a hand. From an outsider's point of view, it might be seen as mannerly (which is a laughable concept, considering who's attached to the hand), but for Severus, it's practical. Once, shaking hands was a sign of truce and trust: gripping of wrists to make a show of being unarmed. His hand out, whether Lucius accepts or not, sets the tone. I'm going to be painfully civil. What about you?