I'm not sure if I want to be 30 minutes late for class.
What would happens if you are late for class?
I won't be able to sit with my friends
Well, it's your responsibility to get to class on time, which obviously has benefits like getting to choose where to sit and who you get to sit with. However, sometimes there is unforeseeable circumstances and there is nothing you can do about it.
I will try not to be late then.
Sure, you have always been very responsible and on time. I love that about you because it's part of your character. It shows people how reliable you are, and that means a lot to me.