A Broken Heart

Prom is this weekend in Casa Grande at our local high school. So When I went to pick Courtney up at preschool at the high school she announced proudly that she was going to Prom. So here is how the conversation went.
"Who are you going to Prom with?"
"I am going with my teacher Michael"
"Who is Michael?"
"Oh, he is one of my teachers and he said that we are going to prom together tomorrow"
I am starting to dismiss it a little, thinking this is no big deal...so I say
"Courtney, you don't even know what Prom is"
"Yes, Michael said that I have to wear a pretty dress and do my hair pretty then come here and have a dance"
So, I am thinking, ok...she really does know what prom is
"Courtney, honey prom is only for the older kids, not for younger ones"
She starts to become persistent that she was told by Michael to come to prom with him tomorrow and after a few minutes she realizes that she can't go and bursts into tears. She just cries and cries saying "Michael told me to come and to wear a dress"...meanwhile I am telling her she can dress up for a date with her dad (she was so not interested in that, because he's not Michael and it's not the same...)
So, here I am with my 4 year old crying from a broken heart while I just want to kill this "teacher Michael" who broke her heart. So then I think, was he telling her this thinking she would forget about it, or to be mean, why would he do this to her? Then once I am rational I realize that it was all a misunderstanding and I am sure he didn't mean to break Courtney's heart...it is just that "mama bear" instinct that we have to protect our kids from heartache.
I realize that many boys will break my girls' hearts in their lifetime, but I didn't think it would start so early!