Hero is a police officer/sheriff/special ops guy/ex-marine/army veteran and heroine is a store owner/doctor/accountant/artist/unspoilt heiress.
Together they find the hideout of a Villain!
Hero tells heroine: stay in the car/stay in the house/stay behind the trash bin/just stay the hell back while I go deal with the bad guy since I have experience doing this.
Heroine tells hero: I will not!/make me!/how dare you leave me behind!
Hero: (very reasonably) It’s for your own safety/don’t want you distracting me/you can’t fight/they can take you hostage you silly idiot!
Heroine: (grumble, grumble) Fine.
Hero leaves, then heroine: Aha! Fool, you thought to leave me behind!/You don’t think I can help you? I’m a Modern Woman! I’ll show you!
Heroine follows hero, Villain seizes heroine just as hero has upper hand, hero ends up getting shot, stabbed or seriously beaten up, heroine cries and curses; then after hero has suffered much, heroine suddenly thinks of a way to distract Villain and his evil minions, hero gets upper hand again and then finally has to fight through dozens of villains to resue heroine…
All this when he could have just walked out unscathed hours ago!