He just said please leave UA out of it. He's talking to him isn't he?
He's being dumb here. He's confronting a villain by himself that he knows very little about. But that's part of the problem of having this encounter in the first place. There's very little that may actually happen from this. Gentle could still be all "Oh I'm not who you think I am?" And back off. And then not show up. Deku asking him not to show up and then still hoping a villain will keep his word and never telling anyone cause he wants the festival to continue is still problematic. It'll mean he knew the guy was lurking and let him go. And the festival could still get invaded and the school still looks bad.
The intention is to make sure he does not get into UA to begin with. Gentle already told La Brava to turn on the camera so he's not backing down here. What's the point of playing dumb when there's an immediate threat sitting right in front of you?
–- Update From New Post Merge ---
@TLC:
What a great hero Deku is asking a villain to walk away and go free potentially hurting innocent civilians someday all to protect Jiro's special day instead of you know trying to capture or report him.
Did you speedread through this arc or are you just being stupid? It was more of a threat than an actual plea.