Professor Clark asks to talk to you

You were just about ready to start chatting up the mousy girl when Professor Clark approached you and said, "Bryan, I'd like a word with you, if you have a moment."

Fuck! There goes your plans for getting off. You're going to get chewed out for being late to class again!

As the last of the students leaves the classroom, you approach the table where Professor Clark is standing, gathering his lecture notes.

You really haven't interacted much with him, and you wonder why he could want to talk to you. Immediately your mind goes to the second day of class when you and another guy started feeling each other up under the tables as you sat next to each other. You tried to be discreet, but it did look like Professor Clark may have noticed something going on. Had that guy stayed in that class, no doubt you would have eventually done something to get caught, but he dropped the class a couple of days later. Maybe you were too much of a distraction for his studies....

Anyway, Clark wants to talk to you now. Would it be better to wait for him to speak first, or for you to take the initiative by saying something?