When someone says my name with the correct pronunciation and accent 😳 how do they know my true name

Similar here, my partner and I are mostly talking in English for non-important/silly stuff and switch to French when things said are serious/important. A way to separate real/serious from joking/sarcasm.

This is why, as a native English speaker, I just never express my emotions.

You jest, sir, but this is the reason I purposefully got a British therapist instead of using my native language in therapy.