Of course, Severus had straightened up and taken a step back as soon as Al had started to speak; he remained standing, a silent, supportive presence at Al's back.
When Harry managed to choke out an utterly unconvincing 'Congratulations', following up immediately with a transparently hopeful question about a decade's delay, Severus would have been insulted to the point of fury, if he'd been any less cynical about people's attitudes toward him.
Fortunately for all concerned, especially himself, he knew damned well that - with the exception of Al - nobody liked him, so he wasn't even surprised. Instead of frothing or hexing, he merely murmured serenely, "I am willing to wait for Al, as long as it takes."
Sometimes the best defence was the absolute, unvarnished truth. After all, it wasn't as though he'd ever have - or had ever had - any better chance at anything resembling actual happiness.