A Thief's Proposal

He held the small copper coin in his hand, he began to get nervous. This was much harder than any heist he had ever pulled off. Harder than breaking into that knight's house? Yep. More difficult than simultaneously sneaking into and out of that one prison in the same night? Oh definitely.
He could feel his palms becoming sweating even through his thick leather gloves, the coin becoming hot in his grasp. Then she came through the door and his heart skipped a beat. Alright, you can do this he thought. He stepped forward to greet her.
"Hi sweetie," she said with that beautiful bright smile of hers. He managed a sly smile and took her hand as if to shake it, slipping the coin quietly into her hand. Confused she looked into her palm. A small copper coin, old and tarnished. His coin, his first, the very first coin he ever stole, kept close as a memento. A symbol of his beginnings as a professional thief and burglar. She looked up at him, mouth open, searching for words.
"I...," she stuttered through tears, he smiled again smugly, "Of course I'll marry you! You idiot!" she threw her arms around him in a tight embrace. Phew, that went well he thought fighting back tears.

Execution

It is actually a fairly simple ritual, one that is commonly practised between thieves that are romantically involved. The thief that is conducting the proposal takes the first thing he ever stole, usually kept as a memento or symbol of the beginning of their professional career. A good luck charm typically held onto by most thieves. They then take this object, whether a coin or other small valuable item and slip it into the hand of their lover using the same technique they would use to discreetly pass off an item to a fellow thief. If the receiving thief accepts the item then the proposal is accepted as well and the thieves will be married.

Components and tools

All that is required is the first object the thief stole in his professional career, a common item is a coin as most thieves start their career with minor pickpocketing. Though other items can be used as long as they are small enough to be pressed into the palm of someone's hand.