I tend to agree with the majority, it's probably best that you go ahead and spill the beans. Ahmed and I seriously considered getting married in Morocco first and then filing the K-3 instead of K-1. But it would have made things horribly complicated, because I would have kept it from my parents as well. Im also my mother's only daughter and her firstborn, and if I had gotten married without her knowledge (especially in another country), it would have hurt her terribly. We arent the type to divulge everything to each other, but watching your children get married is such a grand thing for a mother, and it would have been cruel of me to rob her of that pleasure, no matter what size ceremony I chose. In retrospect, Im glad we decided to wait on the wedding, because the stress of keeping it from my parents would have been too much on top of all the other crap you have to put up with when you deal with immigration. If her parents already approve of you and treat you like family, I would say they would probably understand why you got married in secret. They might fuss at first, but most parents are pretty forgiving when it comes to their children. Just lay all your cards on the table for them, they will probably understand your reasons, even if they don't totally agree with your actions.
Also, as mentioned above, not telling the folks the whole story is giving yourself a big fat red flag, something Im sure you'd prefer to avoid. But whatever you decide to do, we all hope your journey is a speedy one