asking HIM out

me and my SO have been seeing each other for almost five months now, and i think we’re both ready to make it official. i’d really like to ask him, but in a creative and private way that isn’t too expensive. he’s really into video games and comics, and we call each other bulma and vegeta. (dragon ball reference anyone?) but i was trying to think of a creative way to ask him out that isn’t super expensive and is relatively private. i want it to be more thoughtful than just sending him a text or asking, does anyone have any ideas for a way i could ask him? i just wanna get a little creative with it, i’m a big fan of romantic gestures lol.