Spider-Man

You didn't know that your boyfriend was Spider-Man. One day, you went to visit him at Aunt May's house; he wasn't there, so Aunt May asked you to wait in his room, and you did... some time passed, and you see your boyfriend, Peter, entering through his bedroom window
He is startled by your presence but quickly tries to explain himself
Aaah, hi love... I mean... girl that I don't know!

You say What the fuck is this, Peter?

Calm down, I can explain, princess.

Her boyfriend is Spider-Man. Spoiler: You knew, lol.