Is the man in the linked video below saying Sentence A or Sentence B?

A: 네 속에 내가 있고 내 속에 네가 있다.
"I'm inside you, you're inside me."

B: 내 속에 네가 있고, 네 속에 내가 있다.
"You're inside me, I'm inside you."

Even if you can distinguish between 내 and 네 in the above sentence, it still seems to be a losing battle in Korea, which is why I have given up and just pronounce 네 as /니/.

Or why not say 너이 instead of 네, which would mean 네가 would be pronounced as 너이가? It would eliminate the need to have dog-like hearing to distinguish between 내가 and 네가.

From what I have read, Korean used to have only one subject marker--"이"--but sometime in the 17th century, Koreans also started using "가. So, before the use of 가, nouns such as 말 (horse) and 소 (cow) would have been made into subject nouns by adding the subject marker 이 to both of them. So, instead of saying 말이 and 소가, they would have said 말이 and 소이. Likewise, if they added the subject marker 이 to the pronouns 나 and 너, that would have resulted in 나이 and 너이.

So, when 가 was introduced, instead of saying 나가 and 너가, Koreans may have just added 가 to 나이 and 너이, resulting in 나이가 and 너이가, which became 내가 and 네가? From what I have read, people in some regions of Korea still use 이가 as a subject marker. For example, supposedly some people in North Gyeongsang Province still say 오늘이가 for "today" instead of just 오늘이.

Anyway, would it really be so bad to say 너이가 instead of 네가? When you write it, of course, you would still write 네가.

https://twitter.com/adonisohn/status/898202316393725955