Thankfully he does not startle as easily as some of the other students, no, but he's still not expecting the sudden company. His eyes widen for that half second before recognition hits, and then he's got his expression schooled back into a careless smile, all studious tension gone in an instant with a quiet laugh.

"Mercedes," he greets, and while he doesn't shy away from her touch by any means, he does turn so he can settle his attention more fully on her. "Appearing in my time of need, as always... But you know, if it's just some alone time you're after, you don't need to go to all the trouble of making excuses."

Because magic practice is obviously just an excuse to spend time with him! It's fine, he definitely gets it. Complete understanding.