The conversation is framed from the point of view of tradition in some parts of the world. Of course the cops won't arrest you if you decide not to get an engagement ring. It's like going to work in flip flops, it's not illegal, just frowned upon in many circles.

These faux-intellectual "I'm a robot, beep boop I don't understand context and I parse conversations like a compiler would, semantic error on line 5" conversations are probably the least productive on this website, and they're unfortunately very common. It's not smart, it's just obtuse.