It feels anything but juvenile to Pepper, rest assured. Eyes lightly closed, she kisses back with a certain slow indulgence, enjoying the fact they're finally doing this sober and in mutual agreement, sighing at the way his tongue strokes hers. Her hands slides up his chest slowly, fingers spread slightly, lingering for a moment over his pectoral and rubbing lazy circles before venturing upward again to cup the side of his neck gently. The burning in her lungs eventually forces her to pull back, but only enough to break the contact between their lips to pull in a deep breath and huff another out with a thready chuckle. "Wow," she deems after a beat, a crooked grin spreading to her mouth.