This time: devotion. Here's a link to other contributions.
Her anticipation mounted as she savoured the prospect of guilty pleasure, the wicked sweetness at the end – ah, she was so near now.
She looked up into his eyes with that fateful longing, her lust so obviously exposed to the young man – this stranger.
"I do this so rarely...." she stammered, "... it's..."
"You did order extra fries and a double cone, didn't you?"
"Yes...it's my one indulgence – just once in a blue moon," she tried to add, but already he had turned away, checking the next order as another car rolled up behind hers.