I say move on her, not the other way around. Every time MC tries something or even flirts, she makes a fool of him.
You said she shows
no interest. You are wrong. Again go through it again, but don't rush.
Here are a couple of examples:
1. If you stay and watch her when she's getting changed she spots you from the corner of her eye. What does she do? She keeps undressing and only after she has her tits in her hands does she turn around and tell him to leave. It was very deliberate. She wanted him to see her that way. Making a fool? no.
2. If you make a proposition to her the same night she say's "I can't" not "I'm not interest" or "brother eww" she says she's unable to, which is not what you say when you aren't interested. Making a fool? no.
3. She puts her hands on the MC multiple times when there is no need and even pulls at his shirt. She's teasing him or she's horny. or both. Making a fool? no.
She even admits to acting inappropriate with him the following morning.