Boyfriend
pronoun, の adjective
A he mister is not just he, it's "mister he," and mister he is your he, your boyfriend.
かれし
The readings are the ones you learned with the kanji.
ねぇ、私、あなたと喋るだけで、いい気分になるわ。あなたって、私にとって本当に理想の彼氏だわ。
You know what, I get in a good mood just from talking to you. You really are my ideal boyfriend.