Sippy cups... brings back memories.
One of my kids was at a family party with his sippy cup full of juice. We told him not to drink from somebody’s old beer can. So, he emptied his sippy cup and filled it with beer. He thought the container was the problem, not the liquid.
That worked fine until he grabbed a beer can that someone had dropped a cigarette butt into.
My nephew at 10 or so grabbed my Coca-Cola spit can and chugged it.
That never happened again in his life. (20 years ago)
Lesson; Don’t mess with things that don’t belong to you......