This thread could be recreated every week, and every time I'd have to insist on my 2 cents.
Pepsi is vile, hateful, angry, hurtful, detestable sludge from the bottom of the filthiest swamp in the world. Okay, so I drink Diet Coke in quantities that would make a doctor cringe. But I don't care. I love, hmm? LOVE Diet Coke, and I hate, hmm? HATE anything Pepsi. Pepsi is disgusting and full of hate. I'd simply laugh at Pepsi if it wasn't posing such a health risk to all of humanity just by the horrid taste of this painful beverage.
If I'm at a restaurant and I order a Diet Coke, and they have the nerve, the audacity, the unmitigated gall, to actually ask me if Diet Pepsi is okay, I'll close my eyes and count to 5, get myself in my happy place to avoid a scene.
If I've left anything unclear, I'll just say I prefer Diet Coke.