No one casual would ask things the way Longbottom seemed to be doing -- just because the tone came out nonchalant didn't mean he was. Snape liked to think that he was good at reading people when it mattered but right here and now, where everything was new and strange it was admittedly more difficult than usual.
Severus scoffed at the idea of being a war hero (for all that Neville disliked him, Snape was also well aware of his own faults, even if he'd never say so to a stranger). He took a moment to look around, getting a sense for the greenhouse and the man in front of him. And -- well. Realistically from what he'd heard and read it didn't really matter here, nothing stuck in this place. But it was a secret he'd never given up before now.
"Does He come back?" Snape asked, but he already knew the answer. But -- fine. He crossed his arms, and looked back at the man. The Longbottoms had been Gryffindors. Probably so was he. "It's been nearly over ten years. Does that satisfy?"