His hand pauses for a second as he rubs her arm in comfort, but he recovers a moment later. Obviously he knows this thing between them isn't exclusive or anything, and he doesn't know if he even needs it to be, but it's different to hear it out of her mouth. It's definitely different for it to be the man Corry told Les she believes is her brother, and now April is telling him the same thing. Is there even anything to say to that? They sit there for a few seconds in silence because that is a ton of new information to take in all at once. 

April is Corry's sister. Half-sister. Whatever. They're related. That's...a lot. He shakes his head after a moment. "Wow," he says, not knowing any other words to describe his overall reaction. "If you want me to be there when you talk to Corry, you can use my place. I don't know if that helps."