Severus could certainly commiserate: being watched by a passel of Potters and a warren of Weasleys certainly wasn't his idea of a good time either.
But it beat dealing with the lot of them on the warpath.
"You know they want to be there because they care about you," he murmured coaxingly into the downturned mop of hair. "If you don't invite them, that's as bad as telling them that you don't care about them."