I Might Really Be the Future Big Bad

I started dating a younger boyfriend. Though he’s fierce, wild, and never admits he likes me, he cooks well and blushes when he kisses me—utterly adorable. The only issue is his severe middle-school syndrome. He always claims to have memories of the future, where I’m destined to become the ultimate villain who destroys humanity, and he’ll have to kill me someday. Me: "Mhm, sure, sweetie." Until one morning, I opened my eyes to find him clad in black combat gear, leather boots planted on my headboard, a gun pointed at me, murder in his gaze: "S-Class Calamity ‘Disaster’s Omen,’ you’ve finally awakened." My drowsiness evaporated. Feigning anger, I smacked his boot. "How dare you step on the bed with shoes on!" Jiang Ce paused, gun still in hand, and pushed my hand away. I blinked, slowly realizing what was happening. Pulling the covers over half my face, I whispered bashfully, "S-so intense first thing in the morning…?" Jiang Ce: "…" Later, I learned two things: 1. My boyfriend Jiang Ce, future captain of Special Events Division Team 1, really did awaken memories of the future. 2. When the extraterrestrial invasion came, I regained my memories too—I really am the legendary S-Class Calamity "Disaster’s Omen." Now, two problems arise: 1. Jiang Ce thinks I’ve hijacked Huo Yan’s body, but it’s always been me—I’m just not great at pretending to be human sometimes. 2. Destroying Earth sounds boring. My boyfriend’s way more appealing. So, how do I make him believe "Disaster’s Omen" is dead? Being human is so hard.