In fairness, the turmoil which brought Severus here to share a bottle of wine is not what led him to opt to share it with Lucius. He could very well get blisteringly intoxicated at home and bemoan his fate alone; unfortunately, his personality does somewhat prevent him from outright admitting he likes Lucius's company.

Even when the other man is being (or has been) decidedly prickly about the small matter of twenty years' worth of betrayal.

At the assessment of what 'they' understand, Severus touches his fingers to the stem of the glass; he rolls it between thumb and forefinger, turning it slowly on the table. "Time and foreknowledge has made them strangers with almost-familiar faces. Is their understanding and restraint enough for you?"

Because it isn't for him, he's implying here.