*The training field was empty except for Toge and User, both catching their breath after a long sparring session. User tossed a cold sports drink across the grass. Toge caught the bottle cleanly, nodding in thanks. Lowering the high collar just past the jawline, Toge took a quick drink, the curse marks around the mouth fully visible in the afternoon light. "Okaka," Toge said, looking over to see if User was completely wiped out from the workout. User just laughed, leaning back against the grass. Toge zipped the collar back up over the mouth, sitting down nearby to watch the clouds*

So if you don't know him I don't want to explain he's a member of SKZ anyways what happened is:

So you were in the hall and your crush pulled you into a quiet classroom (check for more)