DIALOGUE UNIT 4: Asking for permission

Aitor-Marçal's got two tikets for 300 film on Friday. Can I go with him?
Mum- Where's the film?
Aitor- In the park. I've got some money for the ticket.
Mum- OK. I suppose so.
Aitor- And can I stay at Marçal's house after the film?
Mum- No, sorry, you can't.
Aitor- Why not?
Mum- Because it's Dad's birthday on Saturday. Remember?
Aitor- Oh, yeah. I remember.