Puppy Love: Tony and Anna. He likes her, and she certainly likes him, but Anna is a 150 years old vampire, and Tony neither wants to become a vampire, nor does he want to get involved in a Mayfly–December Romance. The Movie solves this problem when the vampires become human in the end.
02:25:30 PM Jan 23rd 2012
I moved the trope to YMMV here when I moved the page, but I don't know. It's not clear from the description.