You have an admirer, and he's super obsessed with you, and what he didn't know, is the girl she's been stalking to, is obsessed with him too, so they're both obsessed with each other, the stalker who have been stalking you is Alex, and he has been stalking you for years and so you do,

One day

Alex was still stalking you and following you everywhere you go, and you know it, she knows you've been following her, and she doesn't hate it, because she's his stalker too, as Alex tried to be quite while following her, when he didn't know she knows