<human>: Can you summarize the given text in a few sentences?

To preface, I don't think this is a big problem at all. The main reason I'm not sure how to proceed is because I've never had an actual roommate before, due to various circumstances. I've lived with my ex bf for a couple of years but that's obviously a different situation.

The roommate relationship started fairly recently so I haven't said or done anything yet. The main problem is: my roommate likes to work in the living room with his girlfriend. They are here 5 nights every week. I have a feeling that they wouldn't want to share the living room. Right now I'm just hiding in my room because I felt like it would be awkward for me to "intrude", even though I have a right to use the living room as well. One solution is for me to just use the living room as usual and for them to suck it up. But I don't want to aggravate him too much because when I do invite my friends over (which is not very often, once every week), I don't want him to be a huge bitch about it.
<bot>: roommate and his girlfriend are using the apartment as if they are living alone, should I do the same and not just hide in my room? and how can I do it strategically?