What do you think about me using the microwave when my roommate was using it as a timer?
Why do you use the microwave when your friend needed it?
I didn't want to use another timer
Roommates are expected to share communal equipment with one another. If you use something that's already being used by them, they could end up feeling disrespected. You'll create tension within your living area.
The shit is over rated.
It's important for you to be considerate of your roommate and vice versa. This will ensure that you don't cause unnecessary tension in the home.