Housemate’s partner living rent free in our house - England

Unsure if this is the right place to post this so sorry if it’s not.

In July 2023 me and my friend moved into a house together, 50/50 everything.

In January 2024, his girlfriend was kicked out of her friends family home where she was living and moved in with us under the impression it was temporary. She’s been here 5 nights a week ever since, commuting from Nottingham to Macclesfield for work.

Due to her status of effectively being homeless, I never raised the issue of money but I’m starting to feel like I can’t move freely around my own property as I feel it’s become their house and I’m just their lodger, even though I found the house and dealt with the estate agents/landlords while he did nothing.

I proposed she contributes £100 to me and £100 to him, which would mean she’s contributing 16.6% of the overall bills despite being here over 70% of the month. He argued that because she cleans the kitchen (she cleans up after herself after cooking every day) that she shouldn’t have to pay anything.

Am I going crazy or do people not have to contribute where they live anymore? I understand her name isn’t on the papers or the bills and it technically becomes sub-letting but I think it’s more than reasonable to ask for £200 when she’d be paying much much more elsewhere on her own.

Again, sorry if this isn’t the right sub, please point me to the correct one if not.