[guesswest]

Since you've clarified that it's herpes - if you use a condom only when she has a visible outbreak, your chances of contracting it would actually be very low.

But even if they weren't, it's just not that big a deal. If it's a serious relationship I say just don't worry about it. I'd live with contracting herpes in a long-term relationship, and certainly in a marriage - it's better than the alternatives.