I usually use boku and my girlfriend sometimes calls me boku, whether she's talking to me or about me to someone else. There's no confusion because she couldn't be using boku to mean herself.

I'm not a linguist, but it seems like there's no grammatical difference between first/second/third person in Japanese - you can consider all the sentences to be in third person.

Thinking of it as 'I' or 'you' is misleading. That's kinda what I'm trying to say in my post: it's more like these are all third-person roles. If you think of 'boku' as more like 'this boy' than 'I' or 'me' it becomes easier to understand I think.

There's some good info about Japanese 1st- and 2nd-person pronouns here, including a brief mention of boku in a 2nd person position, but unfortunately doesn't go into any depth. https://legendsoflocalization.com/personal-pronouns-in-japan...