Keep HT from girlfriend?

[Rodfarva]

I have seriously considered a procedure now for years, and finally I have enough time off work (due to other circumstances), and i've reached the point where I should soon get a buzzcut because I've receded so much. If there's any time to get a HT, I think it's now. My hairloss has bothered me enough through my twenties, perhaps my thirties could get better.
The only problem is, I don't want people to know. I don't know how things will work out in the long run with my girlfriend of two years, and if she was to know and we broke up, she would really have some dirt on me. We know a lot of the same people, and she even has a lot of connections through others to my colleagues. Would it even be possible to pull it off without her knowing? I'd really like to be open and honest with her, but like I said, I don't know if I can trust her if things were to go sour...