Hey Jung Kook! Well I’m not an Ed Sheeran master though: 1. I believe he’s just saying he has found love with a girl that he can basically give his everything too and not just the small secrets of his. I’m sure we all reveal secrets to our partners etc so that’s just what I think it is. 2. “I’ll be your man” is just a different way of saying “I’ll be your boyfriend” so it’s the same same :)