You had to have been exposed to it somehow. If you have HSV2 then somewhere along the way someone did something outside the relationship. Its much harder to spread it from kissing, oral sex, and other means short of penetration, but it isn't impossible. He should get tested to, and get some good information. My best educated guess is that someone strayed even if it was slight. If you really were virgins, and you had been 100% completely monogamous then this wouldn't be happening. STDS in the 50+ crowd are becoming more and more prevelant, because people don't take precautions because they are older, and figure that it won't happen to them and STDs are for the younger set, but they aren't tested nearly as often as younger people, and like you are told by partners that nothing ever happened outside of the marriage. You first test might have been too soon has to be about 16days after encounter. Good luck!