The Importance of Stretching (слэш)

Prompt 2024-61: Fitness trainer AU
When Severus realises that his middle-aged spread has turned into more of a middle-aged seven course meal, he decides that he needs to do something about it, and the new 24/7 gym that opened up seems like the ideal way. The extremely buff former Gryffindors running it have Severus opting to visit late at night instead, in the hopes of getting to workout alone. (Of course, he doesn't - there wouldn't be much of a story if that was the case)