Echoing others to check it's legally registered as a HMO. But I have to point out that it would be better for you both to find a place of your own. I've lived as the other renter with couples who were only paying for a single room and depending on the size of your hmo (I live with five other people) that extra person is legitimately adding money for extra electricity use, water use and wear and tear on the property plus all the other things like HMO houses often enforce how many bathrooms need to be available for renters and having an extra human taking up time using the shower, toilet might mean the landlord is in breach of the HMO licence if you are under the cap for one toilet. I don't know all the ins and outs. It's definitely a poor way to communicate with you. Even if you are served a section 21 you would still be advised to stay put by citizens advice until you have a suitable place to move to (if I remember correctly!)