Suppose you are traveling with one of your friends and he/she is driving you crazy.
Because there is nothing he/she wants to do or see and he/she does not leave you alone.
When you need to be by yourself, what would you say without hurting his/her feelings?
See, would you hate me if I have some alone time?
I'd like to take time to clear my head and think about our tomorrow's plan.
Because I want to spend quality time with you, OK?