"No, no... that's better!" Wade said, reaching out to squeeze her arm. "You don't become perfect in one afternoon. I've had twenty years more practice than you have. And, you know, training by the marksmen in North America. All you've got is me," he offered with a shrug. "You'll get there."
He didn't like seeing people not believe in themselves, and even his own self-doubts he covered up with bravado and impeccable comedic timing. But this sort of thing took a lot of practice and constant dedication to being the absolute best. Wade only took it seriously because of the bigger implication. Because one day he was going to go back and kill someone who really needed to die. He wasn't there yet. He wasn't as good as he wanted to be either.
His expression softened more and he took her by the arms, giving her the most sincere look he could muster, and then started singing "Do you want to blow something up?" to the tune of Do You Want to Build a Snowman.