How is everyone? Good weekend etc?

I had this message from the girl I'm meant to be sharing a 2 bedroom flat with next year, who is also on her year abroad this year and has found a French boyfriend:

'Jeremie is thinking of coming to England from sept to jan/feb ish to be with me. We are going to decide whether is a good idea or not in june so if we decide yes he can have time to get passport and start looking for a job etc. This would mean however that he would be staying with me in our flat. He would pay rent, a bit more to me as would be sharing room but this would also lower your rent. We couldnt really tell cazs i dont think as contract is for two and you arent allowed to do that coz he should be paying council tax as he wouldnt be a student. I wouldnt be all horrible couply and would still be the same value of housemate. Anyway, that is the possible situation. If you are not happy with it then it wouldnt happen and that isnt a prob coz we aint sure whether its a good idea yet or not. What do you think? Whatever you think goes really as J doesnt want to annoy anyone and I want to have good flat situ next year. x'

I am trying to write a reply saying 'no' in the most delicate manner possible - I don't really want to get things off to a bad start by having her resent me not letting her boyfriend stay - but we'd be breaking the contract, and tbh, I think her saying she'd get more rent because he'd stay in her room is laughable.

Any tips?