So this happened to my brother, about 10 years ago. He was around 8 at the time, myself, about 13.
A friend of mine and her mother had invited my mother and I to the movies with them over the March break, and my brother being too young to be left at home alone, was forced to come along.
We went just after lunch, so by the time the movie was out, the theatre was just starting the evening rush.
My friend, her mother and I went to use the washroom before going home, and my brother had to go as well.
Until then, he had accompanied my mother to the women’s washroom, but I guess he thought he was too old for this now and wanted to go into the men’s by himself.
My overly-protective mother was not having this, so she opted for the single room family washroom, where there was a middle aged man waiting by the door.
After a few moments, he told my mother that his young daughter (about the same age as my brother) was inside, and he offered to take my brother to the men’s so they wouldn’t need to wait.
Of course, my mother was a little freaked out and declined his offer. The man waited a bit longer, offered again, and when he was rejected a second time, just walked away.
By this time, my friend and I had returned from the washroom, so my mom knocked on the family washroom door, with no response.
She tried the door, which was unlocked, and found the washroom to be empty. It terrifies me to think of what could have happened to him, had my mother been less paranoid.