Sam was more than happy to kiss her back. Their relationship was definitely one of the unexpected benefits of being stuck in this alternate reality.
His dopey grin turned to laughter when she got excited about the idea of faking a fight. "Sure," he said. "You can even throw a drink in my face, if you want." He didn't mind and it would help sell the bit.
Luckily, one of the waitresses passed by them just then and he squeezed Carol's hand before letting it go and waving the server over so he could grab a couple flutes of champagne from her tray. "Thanks," he said, making a point to give her a blatant once over. It made him feel creepy, he was definitely not that guy, but he'd do whatever the job called for.