It's sweet and touching, but unsanitary and a health hazard. Just imagine how filthy the metal food processors are. McDonald's dirty little secret = employees are too lazy to clean the machines and you have massive bacteria buildup (especially in machines that process daily products). Other chains are not much better.

http://www.viralnova.com/worst-fast-food-items/
https://www.reddit.com/r/AMA/comments/10dbdl/ama_request_someone_who_works_at_mcdonalds_and/

etc, etc...