I also wear the Nutty Buddy and found that it, too, would ride up. Nothing worked. I tried others' suggestions of underpants/jock/compression pant combinations. I even tried losing and gaining weight. I talked to it, even plead with it... but nothing.
Out of desperation, I liberally applied about a half a roll of duct tape, but found that the darn thing would somehow find a way to wriggle itself loose and slide either down into my taint or up onto my belly. This cursed thing.
Contact cement? Nothing. Stitching it directly to my skin? Nope. Honey? It didn't do a thing for the cup, but it brought me back to my younger experimentation days. Ah, youth.
Finally, a friend said to me, "Hey, Elk..." Yeah, that's what my friends call me... "Why don't you use some of these?" and he handed me a box of decking screws. The ones with the square drive. Three-and-a-half inchers. Course thread.
Whoa. The thought seemed extreme... even absurd. But then I remembered reading an article years ago about Boileryard Clarke. You know, THE Boileryard Clarke -- National League umpire in 1893, 1894 and 1896. Yeah, THAT Boileryard Clarke. Well, as it turns out, he revolutionized the male genitalia protection industry by being the first umpire to ever drive screws through his lambskull cup, anchoring them directly to his pubis bones (They used lamb skulls back then. Google it.)
Welp, if it was good enough for ol' Boileryard, it certainly would be good enough for me.
So out to the garage I went with Nutty Buddy in hand and a 20 volt DeWalt hammer drill with a square drive bit. Impact grade. My wife asked if she could come and watch. Not only did I say yes, I told her to rustle up some of the neighborhood kids, too. Once a small but manageable crowd gathered, I went to work. Underpants first, then a jock, then compression pants. I donned my garb while in the privacy of my home, so don't get any ideas that I did anything untoward with the children present. I gently inserted the cup and picked up my drill.
"Alright, kids," I addressed the crowd, "make sure you go back home and try this." Then I confidently and firmly drove in two screws. Yeah, I missed the bone the first time. And the second. I missed the third, fourth and fifth times, too. But on the sixth try, I sent that baby home and in a glorious exclamation of victory akin to Braveheart yelling "Freedom!" or at least Effie Trinket exclaiming, "That is mahogany!" I strutted up to my wife, dipped her in my arms and planted the most macho kiss on her tender rose pedal-like lips. Then I strode confidently past the wide-eyed children, jumped in my truck and drove to my games.
Let me know if it doesn't work for you.