to leave (something) to someone's imagination - this means that instead of telling the person, you will leave them to imagine all of the possibilities. When you use this phrase, it seems like you are being purposely mysterious to the other person.
A. Soooo... what were you up to last Friday when you didn't come to work?
B. How about this? I'll just leave it to your imagination.
A. No, I want to know! Y don't have to be so mysterious about it. C'mon, I promise I won't tell anyone.
to leave (something) to someone's imagination
人に話すのではなく、全ての可能性を想像に任せるということです。このフレーズを使う時は、他人に対して故意に自分のことを秘密にしているような感じです。
例文
A. Soooo... what were you up to last Friday when you didn't come to work?
だから～、仕事に来なかった先週の金曜日は 何をしてたの？
B. How about this? I'll just leave it to your imagination.
そのこと？ご想像にお任せするわ。
A. No, I want to know! Y don't have to be so mysterious about it.
C'mon, I promise I won't tell anyone.
もう、私は知りたいの。そのことをそんなに秘密にすることはないじゃない。
お願い、誰にも言わないって約束するから。
*Take a wild guess.
Taking a wild guess means to randomly guess an answer based on no knowledge or information
For example:
A: Are you a boy or girl?
B:Take a wild guess
A: You didn't give me much information for me to tell.
*Take a wild guess.
当ててみて。
Taking a wild guess は、知識や情報に基づいて、無作為に推測することです。
例文
A: Are you a boy or girl?
あなたは男の子、女の子？
B:Take a wild guess
当ててみて。
A: You didn't give me much information for me to tell.
答えようにも、あまり情報を教えてくれていないじゃない。
A) For me to know and for you to find out ->
You could use the phrase above which implies that you know what the gender of the baby is but they will have to wait until the baby is born to find out
B) You'll have to wait and see ->
By using this phrase you are telling them that you will not reveal the gender they need to wait and find out themselves .
I hope this helps :-)
A) For me to know and for you to find out ->
上のフレーズはあなたが赤ちゃんの性別を知っているが、赤ちゃんが生まれてわかるまで待って欲しいということを伝えるのに使うことができます。
B) You'll have to wait and see ->
この表現を使うことによって、相手にあなたが赤ちゃんの性別を明らかにするつもりはなく、生まれてきてわかるまで待つ必要があるということを伝えています。
役に立ちますように^^
That's for me to know and you to wonder' is a variation of -'that's for me to know and you to find out.' This is a phrase used to reply to a question whose answer the speaker doesn't want to reveal.
A: "John. I was wondering - you seem to have a lot of girlfriends but I thought you were already married?"
B: "Well, that's for me to know and you to wonder!"
That's for me to know and you to wonder' や'that's for me to know and you to find out.' という表現は、話し手が、何かを教えたくない、明かしたくない質問に答えるのに使います。
A: "John. I was wondering - you seem to have a lot of girlfriends but I thought you were already married?"
ジョン、ガールフレンドがたくさんいるみたいだけど、結婚しているんじゃないの？
B: "Well, that's for me to know and you to wonder!"
さて、どうかなぁ。
"It's a secret" seems as if one has something to hide, as if it were top secret information. If one says "Mind your own business", it's a little rude, but direct and to the point. My gender is none of your business, none of your concern or has nothing to do with you, please don't ask me. "It's not relevant", "why would you like to know?" or "what's it to you?". But all these open a discussion because they are questions. So the other person may start to think about why they would like to know. Otherwise, a polite and kind way to communicate they you don't what to reveal your gender would be to keep it honest and say, "I prefer not to say, if you don't mind"
"It's a secret"（秘密です）は、まるで極秘情報であるかのように、何か隠したいことがあるような感じに聞こえます。"Mind your own business"（あなたに関係ない）は、少し無礼ですが、ストレートで的を得た言い方です。
"My gender is none of your business, none of your concern or has nothing to do with you, please don't ask me."
（男か女かはあなたに関係ないでしょう。私に聞かないで）
"It's not relevant"（あなたに関係ないでしょう）
"Why would you like to know?"（どうして知りたいの？）
または、
"What's it to you?"（それがあなたに何の関係があるの？）
ただ、これらは疑問文なので、やり取りが始まります。ですから、相手はどうして知りたいのか考えるかもしれません。
男なのか女なのか言いたくないことを丁寧に優しく伝えたいなら、正直に：
"I prefer not to say, if you don't mind"
（差し支えなければ、あまり言いたくないのです）
と言いましょう。
アメリカ合衆国 
南アフリカ 
イギリス 
