I understand that `intrude` is used in situations in which you are going to ask somebody for their attention or commitment, and `impose (on)` is often used when you are going to ask somebody to do something for you.

Now, which one is used here to show politeness and not wanting to bother others with your presence?
  

    - We're gathering with some friends at 8:30. do you want to come too?
    - Thanks, but I don't want to ____.

I feel like `intrude` is a better fit, but I feel like I've heard `impose` for such a situation from different people.