My Village's Marriage Rite Turns Lovers Murderous

There's a custom in our village. Before getting married, every man has to bring his girlfriend to the chapel to pay their respects. If they come back out safely, it means the couple is destined to live happily together for the rest of their lives. Both of my younger brothers are married at 20. Meanwhile, I'm 30 and still single. It's not that I don't want to settle down, but every girlfriend I bring into the chapel ends up breaking up with me after she comes out. Some even try to kill me. My new girlfriend thinks our village is hopelessly backward and insists on going inside. My father, the village chief, brings her in himself. When they come back out, she pins me to the ground and tries to strangle me to death. I just can't understand it. What's inside that chapel that has the power to change them so drastically? If Dad already knows that every woman who goes inside will come out different, why does he insist on bringing them in?