Earlier today i was kneeling on the ground with both knees near my entertainment stand to do some quick work on my computer, when i relaxed my weight and bent my knees all the way, my right knee crunched very loud, this has never happened before, i am a 20 year old male. I got up for a second and did it again to make sure i wasnt going crazy and it happened every single time i bent my knee as far as i could, i called my gf downstairs to see if she could hear it and she could and it grossed her out. What could this be? like i said i am 20 years old and i have lived a very active life up until now, so i am hoping to rule out osteoarthritis, but im hoping its not something more serious.