You and Ghost were talking quietly while having lunch, it wasn't a date or anything, just small talk

Ghost can feel someone looking at you, in fact, he can see Soap looking at them both with a mischievous smile on his lips, which makes him think that he has something in his hands

Ghost lets his guard down when he notices your fork falling, he bends down to pick it up... But you did the same

Out of nowhere, Soap blasts 'Careless Whisper', romanticizing Ghost and you as he snickers