She looked so beautiful but behind that I wanted to see her face without thinking.
She appeared so beautiful from behind that without thinking, I wanted to see her face.
I suddenly wanted to see her face because she was so beautiful from behind.
思わず - without thinking, without considering
後ろの姿 - back , behindけれど英語だと “from behind”を言います。後ろからの意味です。もし英語で”her behind looked so beautiful”を言ったら”お尻は綺麗”の意味です
綺麗 - beautiful, prettyでもprettyは顔か景色だけだからbeautifulの方がいいです。
後ろの姿がきれいだった - she was so beautiful from behind, she looked so beautiful from behind
~~を覗く - Stare ~~ (英語でもし顔をStare atしたらちょっとストカーっぽいだからlook atの方がいいです)
〜〜ので - because, therefore, so
もし思わず顔を覗きたくなった - I wanted to see her face は 最初だったらbecause 使いますけど後ろ姿綺麗だったので最初にしたら”therefore”か”so”を使います。
I wanted to see her face BECAUSE she looked so beautiful from behind.
She looked so beautiful so/therefore I wanted to see her face.
She looked so beautiful from behind that subconsciously I felt like I just had to see her face.
She seemed to be so attractive from behind that I just had to have a look at her face too.
1) She looked so beautiful from behind that subconsciously I felt like I just had to see her face.
「後ろ姿がとても綺麗だったので思わず彼女の顔を覗かずにはいられなかった。」
2) She seemed to be so attractive from behind that I just had to have a look at her face too.
「後ろ姿がとても魅力的だったので顔を見ずにはいられなかった。」
「彼女は後ろ姿がとても美しい。」は
She looked so beautiful from behind.
She seemed to be so attractive from behind.
と言えます。
「顔を見ずにはいられなかった。」は
I just had to see her face.
I just had to have a look at her face/
などと言えます。
ご参考になれば幸いです！
イギリス 
日本 
