Asking for permission

A: ... it okay if I invite emily to join us?
B: Absolutely, there more the merrier.

A: Do you ....... if I read this section aloud?
B: Not at all, go ahead.

A: .... it be alright if I play some light music while we work?
B: That's fine, as long as it's not too loud.

Student: .... I use the bathroom, please?
Teacher: Yes, you may. Be quick.

A: Do you mind if I eat my sandwitch here?
B: I'd ..... you didn't. It's against the library rules.

Student: May I use my phone to look up this word?
Teacher: ..... afraid not during the lesson, you can use it afterwards.