My mom found mine out because she came up to my bedroom to wake me up when I was visiting. She then proceeded to make snarky little jabs here and there for the rest of the visit.
Dad doesn't know at all, and will never know because I'd be out of the will if he ever found out.
Of course the only way anyone ever would see it is if I was wearing a low-backed evening gown, a swimsuit, or was naked. And since the liklihood of any of that happening around my dad is nil, I think I'm pretty safe.
You could always put a nicotine patch over it.
