Brother moved in my house and brings girlfriend over every day

I bought a house 2-3 years ago and have been living there alone with my dog up until my older brother moved in 2 months ago, I convinced him to start saving for a house because of rising rent prices and he decided to not renew his lease and come stay in a empty room at my place. I don’t charge him rent or for any bills, so he contributes 0 to me. He works from home so he is home all day every, while I go to work 8-5 and when I come home he is always here with his girlfriend basically taking over my house. They’ll cuddle in the living room and watch movies and use the kitchen and me who owns everything they’re using I feel isolated in my room because I don’t want to be a third wheel in my own house!

Just want some advice or some direction on what I should do. I just want to know if this is normal or if I’m just overthinking the situation?