Asking to have tea with 〜てもいい
Grammar Explanation: Permission to do with 〜てもいい

Following a misunderstanding, Cocoa and her friends ended up at the tea house where Syaro works.
- ココア:
- 「せっかくだからお茶してってもいいかな?」
- “Since we have the chance, would it be okay if we had some tea ?”