You decide that it's best to just tell Walker. Sure, he's being an asshole, but the two of you usually get along. Plus you've had lots of practice being the powerless one in your relationship. Maybe if you ask nicely, he'll give your dick back in a week or two. Or, more likely, he'll give you the jock-stick off some hot girl's boyfriend so he can swoop in and bang her. Plus, now that you know this is real, you can always head back to the magic shop later...
You quiet your racing thoughts and gesture for Walker to sit down in your computer chair. He's standing still, with a suspicious look on his face. "Look, just relax, okay? I'll tell you how I did it, but I want you to remember this. And maybe you can help me out too once you've had your fun. Alright?" You stick out your hand for a handshake. Walker shrugs and shakes your hand limply before plopping down in the cushioned swivel seat. He uses one foot to rock himself back and forth. "Okay, I'm listening, cuz." You leave out the part about the magic shop, but otherwise you tell your cousin what you know, recalling what the package said. When Walker asks where it came from, you do add some colorful embellishing -- you say you found it still in the package at a garage sale when you were out for a walk, and thought it might be a collector's item or something. When you got home, you found nothing on google and decided to open it for fun. He seems to buy the white lie; that relaxes you a little. The last thing you need is to tell your rich cousin where a treasure trove of magic items can be purchased.
"Well, that's everything I know, anyways," you say with a quiet exhale. You prop up a few pillows behind you and sit back. Walker is thinking intently. "I mean it sounds like fucking bullshit, but I don't know how else to explain this shit. I guess I'm really gonna try this shit out", he ponders aloud. Your cousin nods towards you with his angular chin. "Yo, [name]. If you were me, what would you pick?" You're not really surprised that Walker is asking for your help. He's paid you to do a few of his college essays already -- it's probably thanks to you he's barely passing. At least these are answers you might benefit from sharing. "Well, I guess I have a few thoughts off the top of my head."
"You could always switch IQ with someone smart. It would make college a breeze, and you're already an athlete." Walker considers this and gestures to keep the ideas coming, not dismissing this thought. "Or, if you want to, you could date any girl you want. Just switch girlfriends with whatever dude she's dating." Walker grins and puts out his fist for a bump. "That's fucking Gucci, dude." You frown a little. "Well, I mean, you don't know what else you're going to switch, so hopefully he hasn't got any problems you could inherit." Your cousin lowers his fist quietly at that, and waits for you to continue. You take a deep breath. "With that in mind, I would really appreciate it if you could fix my... erm... 'problem'. I really wasn't trying to do anything bad, Walker, I just wanted to see if the ring would work. Plus, maybe it would be a good chance to see if the magic works between two other people... there's still a lot we can learn about what the ring can do." The lithe college student nods absentmindedly -- you hope he heard your request.
Walker stands suddenly. "Well, fuck it, cuz. I don't like waiting around all day for shit, I'm just doin' it." He goes to kiss the ring, then he pulls it away quickly. "Forgot you used this shit too, I don't want your fucking nasty cooties." After wiping it on his expensive polo, your cousin kisses the chipped jewel. But what is he changing?