Hcfyk

I need some help understanding the below conversation. A bit of context before this:

• JD asked them to go somewhere and 'call' him when they arrive (he can use powers to realize they are trying to contact him if they say his name and then he can use telepathy to talk to them).

I'll put my understanding of the passage below.

Character 1「 じゃあJDに連絡しましょう」

Character 2「了解だ。JD様、JD様、どうぞおいでください」

Character 3「いや、呼んでも来るわけじゃないぞ。完全にこっくりさんみたいになっているじゃないか」

JD『そもそも「はい」と「いいえ」の書かれた紙がなければボケられぬであろうが』

Character 1「そっちはそっちで連絡入れる前の話が筒抜けみたいなんですけど」

JD『ぐ、偶然じゃ。それで場所には着いたのか』

From what I can see it starts with character 2 calling to him with "JD様、JD様、どうぞおいでください" is the same way used to contact the spirit kokkuri san "コックリさん、コックリさん、おいでください".

Character 3 (liberal translation) - Even if you call him, he won't 'come' here. What do you think we are trying to do, call a kokkuri-san?

JD - How am I meant to "boke" if there is no piece of paper with "Yes" and "No" written on it?

However, I am confused about what character 1 says next.

Looking online it looks like 筒抜け has two definitions:

１ 物音や話し声が、そのまま他の人に聞こえること。また、秘密の内容などがそっくり他に漏れてしまうこと。

２ 人の話などが頭の中にとどまらないで通りぬけてしまうこと

Based on context I don't see how #2 would make any sense, so it most likely is #1 however I'm not quite sure what she is saying. Is she saying that they could hear JD before he made contact with them or something else?

Yes this 筒抜け is used in the sense #1. The funny part of this conversion is that, even though people were trying to summon JD, he had been "there" from the beginning, listening to them, and he could even make a natural tsukkomi to Character 2. Read it like this (it's free translation):

Character 3 (to Character 2): No, JD won't come here if you call him (like that). What you're doing is almost like kokkuri-san (rather than a proper way to summon him)!

JD (to Character 2): And how does such a boke/joke make sense in the first place, when there is no piece of paper with "Yes" and "No" written on it?

Character 1 (to JD): Oh, looks like there's another funny thing. You were listening to everything even though we haven't tried to (properly) contact you yet...