how To Tell Her Parents?

My friend and I have (both 20 yrs old) been talking "seriously" for about 2 months now. We really like each other, we have been on a few "private" dates, but here's the deal, her parents are very strict on her. That don't allow her to date, have guys numbers, even to accept a guys friends request on Facebook, they must approve. If they find out we have been talking behind their backs, it could be bad for her. So, we are trying to find the beat way to tell them or we are trying to put together a scenario, where I accidentally run into them. (I met her and her parents about a year ago. So they do know me. But me and her have just talk as "friends" for these past two years. (they also don't know that)) So, if anyone has any suggestions or ideas, we are open to anything at this point! We really have to do something soon! The stress of us not able to be open about our relationship is hard on both of us and the stress of having to sneak behind her parents back, is getting to her! Thanks everyone!