My baby nephew and brother's girlfriend are visiting but rather than going into my own room to work on my laptop I'm going to do it in the same room as them.
Is there a reason for this?
Yes, because my brother and his family don't let me do what I want and it bothers me. This is me doing what I want.
It's rude to disturb others if you can help it. You should be respectful towards your family members.
I don't agree with their actions, why should I have to respect them?
Disturbing and disrespecting them isn't going to get them to treat you better in the future, rather it might make them upset. If you do have problems with them the perhaps you should discuss them maturely.