Daughter: 「だって、じゃあたんざくの意味がないじゃん」
Daughter: But, in that case tanzaku are meaningless aren't they?
Dad: 「いいのっ」
Dad: It's okay
Daughter: 「なにさ、おとうさんはすぐいいのって言うんだから」
Daughter: What! Because you say it's okay?
I understand すぐ to mean soon/immediately etc. I can't understand what it means in this context.
My guess it that it adds the meaning 'just' as in "am I supposed to believe it's okay just because you say so?". But that's a complete guess and the link with 'soon'/'immediately' seems very tenuous.
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