How long have you been living with your boyfriend?
To qualify as an UP, you will need to be able to provide evidence that you have been legally living together for > 2 years and because of the lack of formal (in the eyes of the law) relationship, they do take a look at this with a fine toothed comb.
Since he has been going to school in the UK, I don't know if you can prove that you have been living together for 2 years.