I let out a "OMG noooooo" on your behalf, OP. I hope this isn't the case and your Dad hasn't actually found it. My condolences...

I feel you, OP. I am paranoid my sibling found my ao3 account. (I handed them my phone to talk to a relative, and there's an above-zero chance they saw ao3 notifications in my email that I was too careless to delete.) They're in their own fandoms and for all I know they're posting fic, too, that is probably a lot spicier than mine, but I just feel so... exposed. I'm tempted to just make a new account but my current brain-eating WIP is a direct sequel to something I wrote under the original username. ARGH.

Holy crap, OP. Did he confront you? Do you have any plausible deniability wiggle room at all?

I'm not very active in fandom these days, but I'd hate for my family to find my fanfic and stuff. It's not even that it's particularly racy, I just don't need them to rag me about it like they would do, or in the case of my parents, lecture me about how it's a waste of time.

This is why I'm glad every day that my entire family doesn't speak English and that their internet habits are very very different from mine. We don't have much to talk about, but damn at least they will NEVER know about my internet persona...