Part-time Job

So today I got a job offer at McDonalds with and after school schedule and this wans the fallowing conversation between me and me step-dad:

Me: silently thinking.

Sd: you are not interested!

Me: I've heard from people that have worked there that it's really exhausting...

Sd: It's 360 euros per month, but the little girl doesn't need to work.

Me: Silently thinking - How can you expect me to raise my grades, take driving lessons and have a part-time job all at the same time?

some times I just don't know when to speak

and when to stay quiet.