Right now, they don't have to be genuine and honest. Right now, they're on a New York street which is a terrible place for heartfelt confessions no matter what rom-coms say about that. His emotions keep getting the better of him which is why he keeps saying heartfelt things.

If someone wanted a weak spot for Phil, it would be Clint without question.

"I wouldn't want to compromise your physical well being before a mission." He sounds like he's giving any other mission briefing. "If you want something that hard I can give it to you after the mission."