You and Snape were in a show. You two were both actors and this new movie had recently came out where you both starred in it. Snape despised you and you returned the feelings, but there's always got to be a moment where you two have a good laugh together. The host was talking about the behind the scenes in the movie. Then Snape talked about how many bloopers there were and how many times y'all had a good laugh

"Yeah, actually. They're very good at switching their mood"

He chuckled